diff --git a/lib/blocklib.php b/lib/blocklib.php
index dc391583aef5..83e8ca7f3561 100644
--- a/lib/blocklib.php
+++ b/lib/blocklib.php
@@ -214,15 +214,17 @@ public function get_addable_blocks() {
             return $this->addableblocks;
         }
 
-        $unaddableblocks = self::get_undeletable_block_types();
+        $undeletableblocks = self::get_undeletable_block_types();
+        $unaddablebythemeblocks = $this->get_unaddable_by_theme_block_types();
         $requiredbythemeblocks = $this->get_required_by_theme_block_types();
         $pageformat = $this->page->pagetype;
         foreach($allblocks as $block) {
             if (!$bi = block_instance($block->name)) {
                 continue;
             }
-            if ($block->visible && !in_array($block->name, $unaddableblocks) &&
+            if ($block->visible && !in_array($block->name, $undeletableblocks) &&
                     !in_array($block->name, $requiredbythemeblocks) &&
+                    !in_array($block->name, $unaddablebythemeblocks) &&
                     $bi->can_block_be_added($this->page) &&
                     ($bi->instance_allow_multiple() || !$this->is_block_present($block->name)) &&
                     blocks_name_allowed_in_format($block->name, $pageformat) &&
@@ -428,6 +430,21 @@ public function get_required_by_theme_block_types() {
         }
     }
 
+    /**
+     * It returns the list of blocks that can't be displayed in the "Add a block" list.
+     * This information is taken from the unaddableblocks theme setting.
+     *
+     * @return array A list with the blocks that won't be displayed in the "Add a block" list.
+     */
+    public function get_unaddable_by_theme_block_types(): array {
+        $unaddablebythemeblocks = [];
+        if (isset($this->page->theme->settings->unaddableblocks) && !empty($this->page->theme->settings->unaddableblocks)) {
+            $unaddablebythemeblocks = array_map('trim', explode(',', $this->page->theme->settings->unaddableblocks));
+        }
+
+        return $unaddablebythemeblocks;
+    }
+
     /**
      * Make this block type undeletable and unaddable.
      *
diff --git a/lib/tests/blocklib_test.php b/lib/tests/blocklib_test.php
index f15ce7b32ad7..a8cc9a7f41f9 100644
--- a/lib/tests/blocklib_test.php
+++ b/lib/tests/blocklib_test.php
@@ -826,6 +826,43 @@ public function test_default_dashboard() {
         $this->assertEquals('8', $mybr[5]->instance->weight);
         $PAGE = $storedpage;
     }
+
+    /**
+     * Test get_unaddable_by_theme_block_types() method to return expected result depending on the theme.
+     *
+     * @covers \block_manager::get_unaddable_by_theme_block_types
+     */
+    public function test_get_unaddable_by_theme_block_types(): void {
+        global $CFG, $PAGE;
+
+        $this->setAdminUser();
+        $this->resetAfterTest();
+        $regionname = 'side-pre';
+        $context = context_system::instance();
+
+        $PAGE->reset_theme_and_output();
+        $CFG->theme = 'boost';
+
+        list($page, $blockmanager) = $this->get_a_page_and_block_manager([$regionname], $context, 'page-type');
+        $blockmanager->load_blocks();
+        $blocks = $blockmanager->get_unaddable_by_theme_block_types();
+        // Assert that a few blocks are excluded for boost theme.
+        $this->assertCount(4, $blocks);
+        $this->assertContains('navigation', $blocks);
+        $this->assertContains('settings', $blocks);
+        $this->assertContains('course_list', $blocks);
+        $this->assertContains('section_links', $blocks);
+
+        // Change to a theme without unaddable blocks.
+        $PAGE->reset_theme_and_output();
+        $CFG->theme = 'classic';
+
+        list($page, $blockmanager) = $this->get_a_page_and_block_manager([$regionname], $context, 'page-type');
+        $blockmanager->load_blocks();
+        $blocks = $blockmanager->get_unaddable_by_theme_block_types();
+        // Assert that no blocks are excluded for classic theme.
+        $this->assertEmpty($blocks);
+    }
 }
 
 /**
diff --git a/lib/upgrade.txt b/lib/upgrade.txt
index b5fdd52d3cc6..a5a9d147d95b 100644
--- a/lib/upgrade.txt
+++ b/lib/upgrade.txt
@@ -163,6 +163,8 @@ current value for a pluginname depending on its status (enabled, disabled, other
   * /renderer.php
   * /rsslib.php
   This default applies both when there is no supplied coverage.php file, and is used to supplement any existing coverage configuration file if one is found.
+* New method get_unaddable_by_theme_block_types() has been added to block_manager class. It uses the 'unaddableblocks' theme setting
+value to get the list of blocks that won't be displayed for a theme.
 
 === 3.11.4 ===
 * A new option dontforcesvgdownload has been added to the $options parameter of the send_file() function.
diff --git a/theme/boost/lang/en/theme_boost.php b/theme/boost/lang/en/theme_boost.php
index 16f509b45d95..2260c455bd4a 100644
--- a/theme/boost/lang/en/theme_boost.php
+++ b/theme/boost/lang/en/theme_boost.php
@@ -50,6 +50,8 @@
 $string['rawscsspre_desc'] = 'In this field you can provide initialising SCSS code, it will be injected before everything else. Most of the time you will use this setting to define variables.';
 $string['region-side-pre'] = 'Right';
 $string['showfooter'] = 'Show footer';
+$string['unaddableblocks'] = 'Unaddable blocks';
+$string['unaddableblocks_desc'] = 'The blocks defined in this field will not be displayed in the "Add a block" list.';
 $string['privacy:metadata:preference:draweropennav'] = 'The user\'s preference for hiding or showing the drawer menu navigation.';
 $string['privacy:drawernavclosed'] = 'The current preference for the navigation drawer is closed.';
 $string['privacy:drawernavopen'] = 'The current preference for the navigation drawer is open.';
diff --git a/theme/boost/settings.php b/theme/boost/settings.php
index 08ddf3d96d7f..46f9d9a4aca3 100644
--- a/theme/boost/settings.php
+++ b/theme/boost/settings.php
@@ -26,6 +26,15 @@
     $settings = new theme_boost_admin_settingspage_tabs('themesettingboost', get_string('configtitle', 'theme_boost'));
     $page = new admin_settingpage('theme_boost_general', get_string('generalsettings', 'theme_boost'));
 
+    // Unaddable blocks.
+    // Blocks to be excluded when this theme is enabled in the "Add a block" list: Administration, Navigation, Courses and
+    // Section links.
+    $default = 'navigation,settings,course_list,section_links';
+    $setting = new admin_setting_configtext('theme_boost/unaddableblocks',
+        get_string('unaddableblocks', 'theme_boost'), get_string('unaddableblocks_desc', 'theme_boost'), $default, PARAM_TEXT);
+    $setting->set_updatedcallback('theme_reset_all_caches');
+    $page->add($setting);
+
     // Preset.
     $name = 'theme_boost/preset';
     $title = get_string('preset', 'theme_boost');
diff --git a/theme/boost/tests/behat/addblock.feature b/theme/boost/tests/behat/addblock.feature
new file mode 100644
index 000000000000..d786b887ef13
--- /dev/null
+++ b/theme/boost/tests/behat/addblock.feature
@@ -0,0 +1,41 @@
+@javascript @theme_boost
+Feature: Add a block using boost theme
+  In order to decide the blocks to display in the Add a block list for a theme
+  As an administrator
+  I need to define them using the unaddableblocks setting
+
+  Background:
+    Given the following "courses" exist:
+      | fullname | shortname |
+      | Course 1 | C1        |
+    And I log in as "admin"
+
+  Scenario: Default blocks defined in unaddableblocks settings are not displayed in the Add a block list
+    Given I am on "Course 1" course homepage with editing mode on
+    When I click on "Add a block" "link"
+    Then I should not see "Administration"
+    And I should not see "Navigation"
+    And I should not see "Courses"
+    And I should not see "Section links"
+    And I should see "Online users"
+
+  Scenario: Admins can change unaddable blocks using the unaddableblocks setting
+    Given the following config values are set as admin:
+      | unaddableblocks | settings,private_files | theme_boost|
+    And I am on "Course 1" course homepage with editing mode on
+    When I click on "Add a block" "link"
+    Then I should not see "Administration"
+    And I should not see "Private files"
+    And I should see "Navigation"
+    And I should see "Courses"
+    And I should see "Section links"
+
+  Scenario: If unaddableblocks settting is empty, no block is excluded from the Add a block list
+    Given the following config values are set as admin:
+      | unaddableblocks |  | theme_boost|
+    And I am on "Course 1" course homepage with editing mode on
+    When I click on "Add a block" "link"
+    Then I should see "Administration"
+    And I should see "Navigation"
+    And I should see "Courses"
+    And I should see "Section links"
diff --git a/theme/boost/version.php b/theme/boost/version.php
index 60cffec1fd70..32de59ba0f36 100644
--- a/theme/boost/version.php
+++ b/theme/boost/version.php
@@ -24,6 +24,6 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version   = 2021052506;
+$plugin->version   = 2022011000;
 $plugin->requires  = 2021052500;
 $plugin->component = 'theme_boost';
diff --git a/theme/classic/settings.php b/theme/classic/settings.php
index 66049cbb6651..40cad98ae81f 100644
--- a/theme/classic/settings.php
+++ b/theme/classic/settings.php
@@ -35,6 +35,12 @@
     $setting->set_updatedcallback('theme_reset_all_caches');
     $page->add($setting);
 
+    // Unaddable blocks.
+    $setting = new admin_setting_configtext('theme_classic/unaddableblocks',
+        get_string('unaddableblocks', 'theme_boost'), get_string('unaddableblocks_desc', 'theme_boost'), '', PARAM_TEXT);
+    $setting->set_updatedcallback('theme_reset_all_caches');
+    $page->add($setting);
+
     // Preset.
     $name = 'theme_classic/preset';
     $title = get_string('preset', 'theme_classic');
diff --git a/theme/classic/tests/behat/addblock.feature b/theme/classic/tests/behat/addblock.feature
new file mode 100644
index 000000000000..01ef799510a9
--- /dev/null
+++ b/theme/classic/tests/behat/addblock.feature
@@ -0,0 +1,32 @@
+@javascript @theme_classic
+Feature: Add a block using classic theme
+  In order to check the blocks to display in the Add a block list for a them
+  As an administrator
+  I need to confirm the unaddableblocks setting is empty for classic.
+
+  Background:
+    Given the following "courses" exist:
+      | fullname | shortname |
+      | Course 1 | C1        |
+    And I log in as "admin"
+
+  Scenario: All the expected blocks are displayed in the Add a block list for classic
+    Given I am on "Course 1" course homepage with editing mode on
+    When I click on "Add a block" "select"
+    Then I should see "Administration"
+    And I should see "Navigation"
+    And I should see "Courses"
+    And I should see "Section links"
+
+  Scenario: Admins can change unaddable blocks using the unaddableblocks setting for classic
+    Given the following config values are set as admin:
+      | unaddableblocks | online_users,private_files,settings | theme_classic|
+    And I am on "Course 1" course homepage with editing mode on
+    When I click on "Add a block" "select"
+    Then I should not see "Online users"
+    And I should not see "Private files"
+    # The settings block is defined as required block for classic, so it will be displayed always.
+    And I should see "Administration"
+    And I should see "Navigation"
+    And I should see "Courses"
+    And I should see "Section links"
diff --git a/theme/classic/version.php b/theme/classic/version.php
index b06814f07e7e..e27729af4ff2 100644
--- a/theme/classic/version.php
+++ b/theme/classic/version.php
@@ -25,7 +25,7 @@
 // This line protects the file from being accessed by a URL directly.
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version = 2021052500;
+$plugin->version = 2022011400;
 $plugin->requires = 2021052500;
 $plugin->component = 'theme_classic';
 $plugin->dependencies = array('theme_boost' => 2021052500);
diff --git a/theme/upgrade.txt b/theme/upgrade.txt
index 605cc11a824c..99583776ec8b 100644
--- a/theme/upgrade.txt
+++ b/theme/upgrade.txt
@@ -3,6 +3,7 @@ information provided here is intended especially for theme designer.
 
 === 4.0 ===
 * A new theme config 'usescourseindex' allows a theme to specify whether it implements and uses course index.
+* A new theme setting 'unaddableblocks' allows admins to define the blocks that won't be displayed in the "Add a block" list.
 
 === 3.11 ===
 * The classname 'viewmode-cobmined' in course/management.php has been changed to 'viewmode-combined'