diff --git a/actionmailer/CHANGELOG.md b/actionmailer/CHANGELOG.md
index 2f99b61b50247..9feca324a37e3 100644
--- a/actionmailer/CHANGELOG.md
+++ b/actionmailer/CHANGELOG.md
@@ -28,8 +28,6 @@
 
 *   Raise an `ActionView::MissingTemplate` exception when no implicit template could be found. *Damien Mathieu*
 
-*   Asynchronously send messages via the Rails Queue *Brian Cardarella*
-
 *   Allow callbacks to be defined in mailers similar to `ActionController::Base`. You can configure default
     settings, headers, attachments, delivery settings or change delivery using
     `before_filter`, `after_filter` etc. *Justin S. Leitgeb*
diff --git a/actionmailer/lib/action_mailer.rb b/actionmailer/lib/action_mailer.rb
index a9642dc695d16..cfbe2f1cbd2b7 100644
--- a/actionmailer/lib/action_mailer.rb
+++ b/actionmailer/lib/action_mailer.rb
@@ -44,5 +44,4 @@ module ActionMailer
   autoload :MailHelper
   autoload :TestCase
   autoload :TestHelper
-  autoload :QueuedMessage
 end
diff --git a/actionmailer/lib/action_mailer/base.rb b/actionmailer/lib/action_mailer/base.rb
index 4a61bac0a52a3..a3c0b2c6bdd24 100644
--- a/actionmailer/lib/action_mailer/base.rb
+++ b/actionmailer/lib/action_mailer/base.rb
@@ -1,10 +1,8 @@
 require 'mail'
-require 'action_mailer/queued_message'
 require 'action_mailer/collector'
 require 'active_support/core_ext/string/inflections'
 require 'active_support/core_ext/hash/except'
 require 'active_support/core_ext/module/anonymous'
-require 'active_support/queueing'
 require 'action_mailer/log_subscriber'
 
 module ActionMailer
@@ -361,8 +359,6 @@ module ActionMailer
   #
   # * <tt>deliveries</tt> - Keeps an array of all the emails sent out through the Action Mailer with
   #   <tt>delivery_method :test</tt>. Most useful for unit and functional testing.
-  #
-  # * <tt>queue</> - The queue that will be used to deliver the mail. The queue should expect a job that responds to <tt>run</tt>.
   class Base < AbstractController::Base
     include DeliveryMethods
     abstract!
@@ -389,9 +385,6 @@ class Base < AbstractController::Base
       parts_order:  [ "text/plain", "text/enriched", "text/html" ]
     }.freeze
 
-    class_attribute :queue
-    self.queue = ActiveSupport::SynchronousQueue.new
-
     class << self
       # Register one or more Observers which will be notified when mail is delivered.
       def register_observers(*observers)
@@ -483,8 +476,8 @@ def set_payload_for_mail(payload, mail) #:nodoc:
       end
 
       def method_missing(method_name, *args)
-        if action_methods.include?(method_name.to_s)
-          QueuedMessage.new(queue, self, method_name, *args)
+        if respond_to?(method_name)
+          new(method_name, *args).message
         else
           super
         end
diff --git a/actionmailer/lib/action_mailer/queued_message.rb b/actionmailer/lib/action_mailer/queued_message.rb
deleted file mode 100644
index 8d200617c4513..0000000000000
--- a/actionmailer/lib/action_mailer/queued_message.rb
+++ /dev/null
@@ -1,37 +0,0 @@
-require 'delegate'
-
-module ActionMailer
-  class QueuedMessage < ::Delegator
-    attr_reader :queue
-
-    def initialize(queue, mailer_class, method_name, *args)
-      @queue = queue
-      @job   = DeliveryJob.new(mailer_class, method_name, args)
-    end
-
-    def __getobj__
-      @job.message
-    end
-
-    # Queues the message for delivery.
-    def deliver
-      tap { @queue.push @job }
-    end
-
-    class DeliveryJob
-      def initialize(mailer_class, method_name, args)
-        @mailer_class = mailer_class
-        @method_name  = method_name
-        @args         = args
-      end
-
-      def message
-        @message ||= @mailer_class.send(:new, @method_name, *@args).message
-      end
-
-      def run
-        message.deliver
-      end
-    end
-  end
-end
diff --git a/actionmailer/lib/action_mailer/railtie.rb b/actionmailer/lib/action_mailer/railtie.rb
index 59dc26841fc96..7677ff3a7c3cb 100644
--- a/actionmailer/lib/action_mailer/railtie.rb
+++ b/actionmailer/lib/action_mailer/railtie.rb
@@ -19,8 +19,6 @@ class Railtie < Rails::Railtie # :nodoc:
       options.javascripts_dir ||= paths["public/javascripts"].first
       options.stylesheets_dir ||= paths["public/stylesheets"].first
 
-      options.queue ||= app.queue
-
       # make sure readers methods get compiled
       options.asset_host          ||= app.config.asset_host
       options.relative_url_root   ||= app.config.relative_url_root
diff --git a/actionmailer/test/abstract_unit.rb b/actionmailer/test/abstract_unit.rb
index 4b38d4bd31769..99c44179fd69c 100644
--- a/actionmailer/test/abstract_unit.rb
+++ b/actionmailer/test/abstract_unit.rb
@@ -11,7 +11,6 @@
 require 'minitest/autorun'
 require 'action_mailer'
 require 'action_mailer/test_case'
-require 'active_support/queueing'
 
 silence_warnings do
   # These external dependencies have warnings :/
diff --git a/actionmailer/test/base_test.rb b/actionmailer/test/base_test.rb
index 170923673b37f..b06c4653804fd 100644
--- a/actionmailer/test/base_test.rb
+++ b/actionmailer/test/base_test.rb
@@ -3,13 +3,11 @@
 require 'set'
 
 require 'action_dispatch'
-require 'active_support/queueing'
 require 'active_support/time'
 
 require 'mailers/base_mailer'
 require 'mailers/proc_mailer'
 require 'mailers/asset_mailer'
-require 'mailers/async_mailer'
 
 class BaseTest < ActiveSupport::TestCase
   def teardown
@@ -422,17 +420,6 @@ def teardown
     assert_equal(1, BaseMailer.deliveries.length)
   end
 
-  test "delivering message asynchronously" do
-    AsyncMailer.delivery_method = :test
-    AsyncMailer.deliveries.clear
-
-    AsyncMailer.welcome.deliver
-    assert_equal 0, AsyncMailer.deliveries.length
-
-    AsyncMailer.queue.drain
-    assert_equal 1, AsyncMailer.deliveries.length
-  end
-
   test "calling deliver, ActionMailer should yield back to mail to let it call :do_delivery on itself" do
     mail = Mail::Message.new
     mail.expects(:do_delivery).once
diff --git a/actionmailer/test/mailers/async_mailer.rb b/actionmailer/test/mailers/async_mailer.rb
deleted file mode 100644
index c21a464f386e0..0000000000000
--- a/actionmailer/test/mailers/async_mailer.rb
+++ /dev/null
@@ -1,3 +0,0 @@
-class AsyncMailer < BaseMailer
-  self.queue = ActiveSupport::TestQueue.new
-end
diff --git a/actionpack/test/controller/assert_select_test.rb b/actionpack/test/controller/assert_select_test.rb
index 38598a520cba6..3d667f0a2ffad 100644
--- a/actionpack/test/controller/assert_select_test.rb
+++ b/actionpack/test/controller/assert_select_test.rb
@@ -10,16 +10,6 @@
 require 'action_mailer'
 ActionMailer::Base.view_paths = FIXTURE_LOAD_PATH
 
-class SynchronousQueue < Queue
-  def push(job)
-    job.run
-  end
-  alias <<  push
-  alias enq push
-end
-
-ActionMailer::Base.queue = SynchronousQueue.new
-
 class AssertSelectTest < ActionController::TestCase
   Assertion = ActiveSupport::TestCase::Assertion
 
diff --git a/activesupport/lib/active_support/queueing.rb b/activesupport/lib/active_support/queueing.rb
deleted file mode 100644
index a89a48d0579fb..0000000000000
--- a/activesupport/lib/active_support/queueing.rb
+++ /dev/null
@@ -1,105 +0,0 @@
-require 'delegate'
-require 'thread'
-
-module ActiveSupport
-  # A Queue that simply inherits from STDLIB's Queue. When this
-  # queue is used, Rails automatically starts a job runner in a
-  # background thread.
-  class Queue < ::Queue
-    attr_writer :consumer
-
-    def initialize(consumer_options = {})
-      super()
-      @consumer_options = consumer_options
-    end
-
-    def consumer
-      @consumer ||= ThreadedQueueConsumer.new(self, @consumer_options)
-    end
-
-    # Drain the queue, running all jobs in a different thread. This method
-    # may not be available on production queues.
-    def drain
-      # run the jobs in a separate thread so assumptions of synchronous
-      # jobs are caught in test mode.
-      consumer.drain
-    end
-  end
-
-  class SynchronousQueue < Queue
-    def push(job)
-      super.tap { drain }
-    end
-    alias <<  push
-    alias enq push
-  end
-
-  # In test mode, the Rails queue is backed by an Array so that assertions
-  # can be made about its contents. The test queue provides a +jobs+
-  # method to make assertions about the queue's contents and a +drain+
-  # method to drain the queue and run the jobs.
-  #
-  # Jobs are run in a separate thread to catch mistakes where code
-  # assumes that the job is run in the same thread.
-  class TestQueue < Queue
-    # Get a list of the jobs off this queue. This method may not be
-    # available on production queues.
-    def jobs
-      @que.dup
-    end
-
-    # Marshal and unmarshal job before pushing it onto the queue.  This will
-    # raise an exception on any attempts in tests to push jobs that can't (or
-    # shouldn't) be marshalled.
-    def push(job)
-      super Marshal.load(Marshal.dump(job))
-    end
-  end
-
-  # The threaded consumer will run jobs in a background thread in
-  # development mode or in a VM where running jobs on a thread in
-  # production mode makes sense.
-  #
-  # When the process exits, the consumer pushes a nil onto the
-  # queue and joins the thread, which will ensure that all jobs
-  # are executed before the process finally dies.
-  class ThreadedQueueConsumer
-    attr_accessor :logger
-
-    def initialize(queue, options = {})
-      @queue = queue
-      @logger = options[:logger]
-      @fallback_logger = Logger.new($stderr)
-    end
-
-    def start
-      @thread = Thread.new { consume }
-      self
-    end
-
-    def shutdown
-      @queue.push nil
-      @thread.join
-    end
-
-    def drain
-      @queue.pop.run until @queue.empty?
-    end
-
-    def consume
-      while job = @queue.pop
-        run job
-      end
-    end
-
-    def run(job)
-      job.run
-    rescue Exception => exception
-      handle_exception job, exception
-    end
-
-    def handle_exception(job, exception)
-      (logger || @fallback_logger).error "Job Error: #{job.inspect}\n#{exception.message}\n#{exception.backtrace.join("\n")}"
-    end
-  end
-end
diff --git a/activesupport/test/queueing/synchronous_queue_test.rb b/activesupport/test/queueing/synchronous_queue_test.rb
deleted file mode 100644
index 86c39d0f6cf53..0000000000000
--- a/activesupport/test/queueing/synchronous_queue_test.rb
+++ /dev/null
@@ -1,27 +0,0 @@
-require 'abstract_unit'
-require 'active_support/queueing'
-
-class SynchronousQueueTest < ActiveSupport::TestCase
-  class Job
-    attr_reader :ran
-    def run; @ran = true end
-  end
-
-  class ExceptionRaisingJob
-    def run; raise end
-  end
-
-  def setup
-    @queue = ActiveSupport::SynchronousQueue.new
-  end
-
-  def test_runs_jobs_immediately
-    job = Job.new
-    @queue.push job
-    assert job.ran
-
-    assert_raises RuntimeError do
-      @queue.push ExceptionRaisingJob.new
-    end
-  end
-end
diff --git a/activesupport/test/queueing/test_queue_test.rb b/activesupport/test/queueing/test_queue_test.rb
deleted file mode 100644
index 451fb68d3ec31..0000000000000
--- a/activesupport/test/queueing/test_queue_test.rb
+++ /dev/null
@@ -1,146 +0,0 @@
-require 'abstract_unit'
-require 'active_support/queueing'
-
-class TestQueueTest < ActiveSupport::TestCase
-  def setup
-    @queue = ActiveSupport::TestQueue.new
-  end
-
-  class ExceptionRaisingJob
-    def run
-      raise
-    end
-  end
-
-  def test_drain_raises_exceptions_from_running_jobs
-    @queue.push ExceptionRaisingJob.new
-    assert_raises(RuntimeError) { @queue.drain }
-  end
-
-  def test_jobs
-    @queue.push 1
-    @queue.push 2
-    assert_equal [1,2], @queue.jobs
-  end
-
-  class EquivalentJob
-    def initialize
-      @initial_id = self.object_id
-    end
-
-    def run
-    end
-
-    def ==(other)
-      other.same_initial_id?(@initial_id)
-    end
-
-    def same_initial_id?(other_id)
-      other_id == @initial_id
-    end
-  end
-
-  def test_contents
-    job = EquivalentJob.new
-    assert @queue.empty?
-    @queue.push job
-    refute @queue.empty?
-    assert_equal job, @queue.pop
-  end
-
-  class ProcessingJob
-    def self.clear_processed
-      @processed = []
-    end
-
-    def self.processed
-      @processed
-    end
-
-    def initialize(object)
-      @object = object
-    end
-
-    def run
-      self.class.processed << @object
-    end
-  end
-
-  def test_order
-    ProcessingJob.clear_processed
-    job1 = ProcessingJob.new(1)
-    job2 = ProcessingJob.new(2)
-
-    @queue.push job1
-    @queue.push job2
-    @queue.drain
-
-    assert_equal [1,2], ProcessingJob.processed
-  end
-
-  class ThreadTrackingJob
-    attr_reader :thread_id
-
-    def run
-      @thread_id = Thread.current.object_id
-    end
-
-    def ran?
-      @thread_id
-    end
-  end
-
-  def test_drain
-    @queue.push ThreadTrackingJob.new
-    job = @queue.jobs.last
-    @queue.drain
-
-    assert @queue.empty?
-    assert job.ran?, "The job runs synchronously when the queue is drained"
-    assert_equal job.thread_id, Thread.current.object_id
-  end
-
-  class IdentifiableJob
-    def initialize(id)
-      @id = id
-    end
-
-    def ==(other)
-      other.same_id?(@id)
-    end
-
-    def same_id?(other_id)
-      other_id == @id
-    end
-
-    def run
-    end
-  end
-
-  def test_queue_can_be_observed
-    jobs = (1..10).map do |id|
-      IdentifiableJob.new(id)
-    end
-
-    jobs.each do |job|
-      @queue.push job
-    end
-
-    assert_equal jobs, @queue.jobs
-  end
-
-  def test_adding_an_unmarshallable_job
-    anonymous_class_instance = Struct.new(:run).new
-
-    assert_raises TypeError do
-      @queue.push anonymous_class_instance
-    end
-  end
-
-  def test_attempting_to_add_a_reference_to_itself
-    job = {reference: @queue}
-    assert_raises TypeError do
-      @queue.push job
-    end
-  end
-end
diff --git a/activesupport/test/queueing/threaded_consumer_test.rb b/activesupport/test/queueing/threaded_consumer_test.rb
deleted file mode 100644
index a3ca46a261cf8..0000000000000
--- a/activesupport/test/queueing/threaded_consumer_test.rb
+++ /dev/null
@@ -1,110 +0,0 @@
-require 'abstract_unit'
-require 'active_support/queueing'
-require "active_support/log_subscriber/test_helper"
-
-class TestThreadConsumer < ActiveSupport::TestCase
-  class Job
-    attr_reader :id
-    def initialize(id = 1, &block)
-      @id = id
-      @block = block
-    end
-
-    def run
-      @block.call if @block
-    end
-  end
-
-  def setup
-    @logger = ActiveSupport::LogSubscriber::TestHelper::MockLogger.new
-    @queue = ActiveSupport::Queue.new(logger: @logger)
-  end
-
-  def teardown
-    @queue.drain
-  end
-
-  test "the jobs are executed" do
-    ran = false
-    job = Job.new { ran = true }
-
-    @queue.push job
-    @queue.drain
-
-    assert_equal true, ran
-  end
-
-  test "the jobs are not executed synchronously" do
-    run, ran = Queue.new, Queue.new
-    job = Job.new { ran.push run.pop }
-
-    @queue.consumer.start
-    @queue.push job
-    assert ran.empty?
-
-    run.push true
-    assert_equal true, ran.pop
-  end
-
-  test "shutting down the queue synchronously drains the jobs" do
-    ran = false
-    job = Job.new do
-      sleep 0.1
-      ran = true
-    end
-
-    @queue.consumer.start
-    @queue.push job
-    assert_equal false, ran
-
-    @queue.consumer.shutdown
-    assert_equal true, ran
-  end
-
-  test "log job that raises an exception" do
-    job = Job.new { raise "RuntimeError: Error!" }
-
-    @queue.push job
-    consume_queue @queue
-
-    assert_equal 1, @logger.logged(:error).size
-    assert_match "Job Error: #{job.inspect}\nRuntimeError: Error!", @logger.logged(:error).last
-  end
-
-  test "logger defaults to stderr" do
-    begin
-      $stderr, old_stderr = StringIO.new, $stderr
-      queue = ActiveSupport::Queue.new
-      queue.push Job.new { raise "RuntimeError: Error!" }
-      consume_queue queue
-      assert_match 'Job Error', $stderr.string
-    ensure
-      $stderr = old_stderr
-    end
-  end
-
-  test "test overriding exception handling" do
-    @queue.consumer.instance_eval do
-      def handle_exception(job, exception)
-        @last_error = exception.message
-      end
-
-      def last_error
-        @last_error
-      end
-    end
-
-    job = Job.new { raise "RuntimeError: Error!" }
-
-    @queue.push job
-    consume_queue @queue
-
-    assert_equal "RuntimeError: Error!", @queue.consumer.last_error
-  end
-
-  private
-    def consume_queue(queue)
-      queue.push nil
-      queue.consumer.consume
-    end
-end
diff --git a/guides/source/4_0_release_notes.md b/guides/source/4_0_release_notes.md
index 55ac4bca871c6..597ac99be0764 100644
--- a/guides/source/4_0_release_notes.md
+++ b/guides/source/4_0_release_notes.md
@@ -5,7 +5,6 @@ Highlights in Rails 4.0:
 
 * Ruby 1.9.3 only
 * Strong Parameters
-* Queue API
 * Turbolinks
 * Russian Doll Caching
 * Asynchronous Mailers
@@ -88,8 +87,6 @@ Please refer to the [Changelog](https://github.com/rails/rails/blob/master/railt
 
 * Threadsafe on by default
 
-* Add `Rails.queue` for processing jobs in the background.
-
 ### Deprecations
 
 * `config.threadsafe!` is deprecated in favor of `config.eager_load` which provides a more fine grained control on what is eager loaded.
@@ -103,8 +100,6 @@ Please refer to the [Changelog](https://github.com/rails/rails/blob/master/actio
 
 ### Notable changes
 
-* Asynchronously send messages via the Rails Queue. ([Pull Request](https://github.com/rails/rails/pull/6839))
-
 ### Deprecations
 
 Active Model
diff --git a/guides/source/action_mailer_basics.md b/guides/source/action_mailer_basics.md
index 6bb3439e5ed92..795afd0150658 100644
--- a/guides/source/action_mailer_basics.md
+++ b/guides/source/action_mailer_basics.md
@@ -575,26 +575,3 @@ end
 ```
 
 In the test we send the email and store the returned object in the `email` variable. We then ensure that it was sent (the first assert), then, in the second batch of assertions, we ensure that the email does indeed contain what we expect.
-
-Asynchronous
-------------
-
-Rails provides a Synchronous Queue by default. If you want to use an Asynchronous one you will need to configure an async Queue provider like Resque. Queue providers are supposed to have a Railtie where they configure it's own async queue.
-
-### Custom Queues
-
-If you need a different queue than `Rails.queue` for your mailer you can use `ActionMailer::Base.queue=`:
-
-```ruby
-class WelcomeMailer < ActionMailer::Base
-  self.queue = MyQueue.new
-end
-```
-
-or adding to your `config/environments/$RAILS_ENV.rb`:
-
-```ruby
-config.action_mailer.queue = MyQueue.new
-```
-
-Your custom queue should expect a job that responds to `#run`.
diff --git a/guides/source/configuring.md b/guides/source/configuring.md
index a8e33a2956c6b..6dba76c7b28d9 100644
--- a/guides/source/configuring.md
+++ b/guides/source/configuring.md
@@ -109,10 +109,6 @@ These configuration methods are to be called on a `Rails::Railtie` object, such
 
 * `config.middleware` allows you to configure the application's middleware. This is covered in depth in the [Configuring Middleware](#configuring-middleware) section below.
 
-* `config.queue` configures the default job queue for the application. Defaults to `ActiveSupport::Queue.new` which processes jobs in a background thread. If you change the queue, you're responsible for running the jobs as well.
-
-* `config.queue_consumer` configures a different job consumer for the default queue. Defaults to `ActiveSupport::ThreadedQueueConsumer`. The job consumer must respond to `start`.
-
 * `config.reload_classes_only_on_change` enables or disables reloading of classes only when tracked files change. By default tracks everything on autoload paths and is set to true. If `config.cache_classes` is true, this option is ignored.
 
 * `config.secret_key_base` used for specifying a key which allows sessions for the application to be verified against a known secure key to prevent tampering. Applications get `config.secret_key_base` initialized to a random key in `config/initializers/secret_token.rb`.
@@ -431,11 +427,6 @@ There are a number of settings available on `config.action_mailer`:
     config.action_mailer.interceptors = ["MailInterceptor"]
     ```
 
-* `config.action_mailer.queue` registers the queue that will be used to deliver the mail.
-```ruby
-config.action_mailer.queue = SomeQueue.new
-```
-
 ### Configuring Active Support
 
 There are a few configuration options available in Active Support:
diff --git a/railties/CHANGELOG.md b/railties/CHANGELOG.md
index e60c26d1324fe..3dd2944da359a 100644
--- a/railties/CHANGELOG.md
+++ b/railties/CHANGELOG.md
@@ -122,10 +122,6 @@
 
 *   Load all environments available in `config.paths["config/environments"]`. *Piotr Sarnacki*
 
-*   Add `config.queue_consumer` to change the job queue consumer from the default `ActiveSupport::ThreadedQueueConsumer`. *Carlos Antonio da Silva*
-
-*   Add `Rails.queue` for processing jobs in the background. *Yehuda Katz*
-
 *   Remove Rack::SSL in favour of ActionDispatch::SSL. *Rafael Mendonça França*
 
 *   Remove Active Resource from Rails framework. *Prem Sichangrist*
diff --git a/railties/lib/rails.rb b/railties/lib/rails.rb
index ac8e84e366a62..bb98bbe5bfdc2 100644
--- a/railties/lib/rails.rb
+++ b/railties/lib/rails.rb
@@ -32,25 +32,6 @@ def configuration
       application.config
     end
 
-    # Rails.queue is the application's queue. You can push a job onto
-    # the queue by:
-    #
-    #   Rails.queue.push job
-    #
-    # A job is an object that responds to +run+. Queue consumers will
-    # pop jobs off of the queue and invoke the queue's +run+ method.
-    #
-    # Note that depending on your queue implementation, jobs may not
-    # be executed in the same process as they were created in, and
-    # are never executed in the same thread as they were created in.
-    #
-    # If necessary, a queue implementation may need to serialize your
-    # job for distribution to another process. The documentation of
-    # your queue will specify the requirements for that serialization.
-    def queue
-      application.queue
-    end
-
     def initialize!
       application.initialize!
     end
diff --git a/railties/lib/rails/application.rb b/railties/lib/rails/application.rb
index bf3a26d4003df..9d71bf448d065 100644
--- a/railties/lib/rails/application.rb
+++ b/railties/lib/rails/application.rb
@@ -1,5 +1,4 @@
 require 'fileutils'
-require 'active_support/queueing'
 # FIXME remove DummyKeyGenerator and this require in 4.1
 require 'active_support/key_generator'
 require 'rails/engine'
@@ -68,10 +67,9 @@ def inherited(base)
       end
     end
 
-    attr_accessor :assets, :sandbox, :queue_consumer
+    attr_accessor :assets, :sandbox
     alias_method :sandbox?, :sandbox
     attr_reader :reloaders
-    attr_writer :queue
 
     delegate :default_url_options, :default_url_options=, to: :routes
 
@@ -83,7 +81,6 @@ def initialize
       @env_config       = nil
       @ordered_railties = nil
       @railties         = nil
-      @queue            = nil
     end
 
     # Returns true if the application is initialized.
@@ -228,10 +225,6 @@ def config #:nodoc:
       @config ||= Application::Configuration.new(find_root_with_flag("config.ru", Dir.pwd))
     end
 
-    def queue #:nodoc:
-      @queue ||= config.queue || ActiveSupport::Queue.new
-    end
-
     def to_app #:nodoc:
       self
     end
diff --git a/railties/lib/rails/application/configuration.rb b/railties/lib/rails/application/configuration.rb
index f15fc9296d00d..086fd5ed950d2 100644
--- a/railties/lib/rails/application/configuration.rb
+++ b/railties/lib/rails/application/configuration.rb
@@ -1,6 +1,5 @@
 require 'active_support/core_ext/kernel/reporting'
 require 'active_support/file_update_checker'
-require 'active_support/queueing'
 require 'rails/engine/configuration'
 
 module Rails
@@ -13,7 +12,7 @@ class Configuration < ::Rails::Engine::Configuration
                     :railties_order, :relative_url_root, :secret_key_base, :secret_token,
                     :serve_static_assets, :ssl_options, :static_cache_control, :session_options,
                     :time_zone, :reload_classes_only_on_change,
-                    :queue, :queue_consumer, :beginning_of_week, :filter_redirect
+                    :beginning_of_week, :filter_redirect
 
       attr_writer :log_level
       attr_reader :encoding
@@ -44,8 +43,6 @@ def initialize(*)
         @exceptions_app                = nil
         @autoflush_log                 = true
         @log_formatter                 = ActiveSupport::Logger::SimpleFormatter.new
-        @queue                         = ActiveSupport::SynchronousQueue.new
-        @queue_consumer                = nil
         @eager_load                    = nil
         @secret_token                  = nil
         @secret_key_base               = nil
diff --git a/railties/lib/rails/application/finisher.rb b/railties/lib/rails/application/finisher.rb
index 09902ad597122..872d78d9a4cf4 100644
--- a/railties/lib/rails/application/finisher.rb
+++ b/railties/lib/rails/application/finisher.rb
@@ -96,15 +96,6 @@ module Finisher
           ActiveSupport::Dependencies.unhook!
         end
       end
-
-      initializer :activate_queue_consumer do |app|
-        if config.queue.class == ActiveSupport::Queue
-          app.queue_consumer = config.queue_consumer || config.queue.consumer
-          app.queue_consumer.logger ||= Rails.logger if app.queue_consumer.respond_to?(:logger=)
-          app.queue_consumer.start
-          at_exit { app.queue_consumer.shutdown }
-        end
-      end
     end
   end
 end
diff --git a/railties/lib/rails/generators/rails/app/templates/config/environments/production.rb.tt b/railties/lib/rails/generators/rails/app/templates/config/environments/production.rb.tt
index 593d2acfc7009..68df1d1ec8031 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/environments/production.rb.tt
+++ b/railties/lib/rails/generators/rails/app/templates/config/environments/production.rb.tt
@@ -84,8 +84,4 @@
 
   # Use default logging formatter so that PID and timestamp are not suppressed.
   config.log_formatter = ::Logger::Formatter.new
-
-  # Default the production mode queue to an synchronous queue. You will probably
-  # want to replace this with an out-of-process queueing solution.
-  # config.queue = ActiveSupport::SynchronousQueue.new
 end
diff --git a/railties/lib/rails/generators/rails/app/templates/config/environments/test.rb.tt b/railties/lib/rails/generators/rails/app/templates/config/environments/test.rb.tt
index a5ef0cd9cdf39..3c9c787948a68 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/environments/test.rb.tt
+++ b/railties/lib/rails/generators/rails/app/templates/config/environments/test.rb.tt
@@ -33,7 +33,4 @@
 
   # Print deprecation notices to the stderr.
   config.active_support.deprecation = :stderr
-
-  # Use the synchronous queue to run jobs immediately.
-  config.queue = ActiveSupport::SynchronousQueue.new
 end
diff --git a/railties/test/application/initializers/frameworks_test.rb b/railties/test/application/initializers/frameworks_test.rb
index 40d1655c9b441..bc794e1602389 100644
--- a/railties/test/application/initializers/frameworks_test.rb
+++ b/railties/test/application/initializers/frameworks_test.rb
@@ -50,22 +50,6 @@ def teardown
       assert_equal "test.rails", ActionMailer::Base.default_url_options[:host]
     end
 
-    test "uses the default queue for ActionMailer" do
-      require "#{app_path}/config/environment"
-      assert_kind_of ActiveSupport::Queue, ActionMailer::Base.queue
-    end
-
-    test "allows me to configure queue for ActionMailer" do
-      app_file "config/environments/development.rb", <<-RUBY
-        AppTemplate::Application.configure do
-          config.action_mailer.queue = ActiveSupport::TestQueue.new
-        end
-      RUBY
-
-      require "#{app_path}/config/environment"
-      assert_kind_of ActiveSupport::TestQueue, ActionMailer::Base.queue
-    end
-
     test "does not include url helpers as action methods" do
       app_file "config/routes.rb", <<-RUBY
         AppTemplate::Application.routes.draw do
diff --git a/railties/test/application/queue_test.rb b/railties/test/application/queue_test.rb
deleted file mode 100644
index 219a35da35b93..0000000000000
--- a/railties/test/application/queue_test.rb
+++ /dev/null
@@ -1,154 +0,0 @@
-require 'isolation/abstract_unit'
-
-module ApplicationTests
-  class QueueTest < ActiveSupport::TestCase
-    include ActiveSupport::Testing::Isolation
-
-    def setup
-      build_app
-      boot_rails
-    end
-
-    def teardown
-      teardown_app
-    end
-
-    def app_const
-      @app_const ||= Class.new(Rails::Application)
-    end
-
-    test "the queue is a SynchronousQueue in test mode" do
-      app("test")
-      assert_kind_of ActiveSupport::SynchronousQueue, Rails.application.queue
-      assert_kind_of ActiveSupport::SynchronousQueue, Rails.queue
-    end
-
-    test "the queue is a SynchronousQueue in development mode" do
-      app("development")
-      assert_kind_of ActiveSupport::SynchronousQueue, Rails.application.queue
-      assert_kind_of ActiveSupport::SynchronousQueue, Rails.queue
-    end
-
-    class ThreadTrackingJob
-      def initialize
-        @origin = Thread.current.object_id
-      end
-
-      def run
-        @target = Thread.current.object_id
-      end
-
-      def ran_in_different_thread?
-        @origin != @target
-      end
-
-      def ran?
-        @target
-      end
-    end
-
-    test "in development mode, an enqueued job will be processed in the same thread" do
-      app("development")
-
-      job = ThreadTrackingJob.new
-      Rails.queue.push job
-      sleep 0.1
-
-      assert job.ran?, "Expected job to be run"
-      refute job.ran_in_different_thread?, "Expected job to run in the same thread"
-    end
-
-    test "in test mode, an enqueued job will be processed in the same thread" do
-      app("test")
-
-      job = ThreadTrackingJob.new
-      Rails.queue.push job
-      sleep 0.1
-
-      assert job.ran?, "Expected job to be run"
-      refute job.ran_in_different_thread?, "Expected job to run in the same thread"
-    end
-
-    test "in production, automatically spawn a queue consumer in a background thread" do
-      add_to_env_config "production", <<-RUBY
-        config.queue = ActiveSupport::Queue.new
-      RUBY
-
-      app("production")
-
-      assert_nil Rails.application.config.queue_consumer
-      assert_kind_of ActiveSupport::ThreadedQueueConsumer, Rails.application.queue_consumer
-      assert_equal Rails.logger, Rails.application.queue_consumer.logger
-    end
-
-    test "attempting to marshal a queue will raise an exception" do
-      app("test")
-      assert_raises TypeError do
-        Marshal.dump Rails.queue
-      end
-    end
-
-    def setup_custom_queue
-      add_to_env_config "production", <<-RUBY
-        require "my_queue"
-        config.queue = MyQueue.new
-      RUBY
-
-      app_file "lib/my_queue.rb", <<-RUBY
-        class MyQueue
-          def push(job)
-            job.run
-          end
-        end
-      RUBY
-
-      app("production")
-    end
-
-    test "a custom queue implementation can be provided" do
-      setup_custom_queue
-
-      assert_kind_of MyQueue, Rails.queue
-
-      job = Struct.new(:id, :ran) do
-        def run
-          self.ran = true
-        end
-      end
-
-      job1 = job.new(1)
-      Rails.queue.push job1
-
-      assert_equal true, job1.ran
-    end
-
-    test "a custom consumer implementation can be provided" do
-      add_to_env_config "production", <<-RUBY
-        require "my_queue_consumer"
-        config.queue = ActiveSupport::Queue.new
-        config.queue_consumer = MyQueueConsumer.new
-      RUBY
-
-      app_file "lib/my_queue_consumer.rb", <<-RUBY
-        class MyQueueConsumer
-          attr_reader :started
-
-          def start
-            @started = true
-          end
-        end
-      RUBY
-
-      app("production")
-
-      assert_kind_of MyQueueConsumer, Rails.application.queue_consumer
-      assert Rails.application.queue_consumer.started
-    end
-
-    test "default consumer is not used with custom queue implementation" do
-      setup_custom_queue
-
-      assert_nil Rails.application.queue_consumer
-    end
-  end
-end