diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index edc48bd2aaad7..d25a197562091 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,12 @@
+*   Propagate `save(validate:)` option for `:has_many` associations on autosave.
+
+    `save(validate:)` option is propagated to associated records during `autosave` when `autosave` option is
+    `nil`. Affects only `:has_many` associations.
+
+    Fixes #43400
+
+    *Jacopo Beschi*
+
 *   Add support for setting the filename of the schema or structure dump in the database config.
 
     Applications may now set their the filename or path of the schema / structure dump file in their database configuration.
diff --git a/activerecord/lib/active_record/autosave_association.rb b/activerecord/lib/active_record/autosave_association.rb
index 9e9cc4c79d232..88bb3fae42ef8 100644
--- a/activerecord/lib/active_record/autosave_association.rb
+++ b/activerecord/lib/active_record/autosave_association.rb
@@ -409,7 +409,11 @@ def save_collection_association(reflection)
                 if autosave
                   saved = association.insert_record(record, false)
                 elsif !reflection.nested?
-                  association_saved = association.insert_record(record)
+                  association_saved = if @_save_options.key?(:validate)
+                    association.insert_record(record, @_save_options[:validate])
+                  else
+                    association.insert_record(record)
+                  end
 
                   if reflection.validate?
                     errors.add(reflection.name) unless association_saved
diff --git a/activerecord/lib/active_record/validations.rb b/activerecord/lib/active_record/validations.rb
index 818515b4e02ee..cf5d80a1642fb 100644
--- a/activerecord/lib/active_record/validations.rb
+++ b/activerecord/lib/active_record/validations.rb
@@ -44,13 +44,17 @@ module Validations
     # The regular {ActiveRecord::Base#save}[rdoc-ref:Persistence#save] method is replaced
     # with this when the validations module is mixed in, which it is by default.
     def save(**options)
-      perform_validations(options) ? super : false
+      with_save_options(options) do
+        perform_validations ? super : false
+      end
     end
 
     # Attempts to save the record just like {ActiveRecord::Base#save}[rdoc-ref:Base#save] but
     # will raise an ActiveRecord::RecordInvalid exception instead of returning +false+ if the record is not valid.
     def save!(**options)
-      perform_validations(options) ? super : raise_validation_error
+      with_save_options(options) do
+        perform_validations ? super : raise_validation_error
+      end
     end
 
     # Runs all the validations within the specified context. Returns +true+ if
@@ -72,6 +76,13 @@ def valid?(context = nil)
     alias_method :validate, :valid?
 
   private
+    def with_save_options(options)
+      @_save_options, previous_save_options = options, @_save_options
+      yield
+    ensure
+      @_save_options = previous_save_options
+    end
+
     def default_validation_context
       new_record? ? :create : :update
     end
@@ -80,8 +91,8 @@ def raise_validation_error
       raise(RecordInvalid.new(self))
     end
 
-    def perform_validations(options = {})
-      options[:validate] == false || valid?(options[:context])
+    def perform_validations
+      @_save_options[:validate] == false || valid?(@_save_options[:context])
     end
   end
 end
diff --git a/activerecord/test/cases/autosave_association_test.rb b/activerecord/test/cases/autosave_association_test.rb
index ef5c71dd46b2f..982f7e4db51bb 100644
--- a/activerecord/test/cases/autosave_association_test.rb
+++ b/activerecord/test/cases/autosave_association_test.rb
@@ -1847,6 +1847,30 @@ def test_validations_still_fire_on_unchanged_association_with_custom_validation_
     assert pirate.valid?
     assert_not pirate.valid?(:conference)
   end
+
+  test "propagates (validate: false) option to associations when autosave is nil" do
+    pirate = SpacePirate.create!
+    pirate.birds.build
+
+    assert_equal false, pirate.save
+    assert_equal true,  pirate.save(validate: false)
+  end
+
+  test "propagates (validate: false) option to associations when autosave is true" do
+    pirate = SpacePirate.create!
+    pirate.birds_with_autosave.build
+
+    assert_equal false, pirate.save
+    assert_equal true,  pirate.save(validate: false)
+  end
+
+  test "propagates (validate: false) option to associations when autosave is false" do
+    pirate = SpacePirate.create!
+    pirate.birds_without_autosave.build
+
+    assert_equal false, pirate.save
+    assert_equal true, pirate.save(validate: false)
+  end
 end
 
 class TestAutosaveAssociationValidationsOnAHasOneAssociation < ActiveRecord::TestCase
diff --git a/activerecord/test/models/pirate.rb b/activerecord/test/models/pirate.rb
index 6b903bc19f633..56c86d4165b67 100644
--- a/activerecord/test/models/pirate.rb
+++ b/activerecord/test/models/pirate.rb
@@ -109,6 +109,8 @@ class SpacePirate < ActiveRecord::Base
   has_one :ship, foreign_key: :pirate_id
   has_one :ship_with_annotation, -> { annotate("that is a rocket") }, class_name: :Ship, foreign_key: :pirate_id
   has_many :birds, foreign_key: :pirate_id
+  has_many :birds_with_autosave, foreign_key: :pirate_id, autosave: true, class_name: :Bird
+  has_many :birds_without_autosave, foreign_key: :pirate_id, autosave: false, class_name: :Bird
   has_many :birds_with_annotation, -> { annotate("that are also parrots") }, class_name: :Bird, foreign_key: :pirate_id
   has_many :treasures, as: :looter
   has_many :treasure_estimates, through: :treasures, source: :price_estimates