diff --git a/.upgradenotes/MDL-74939-2024053010552599.yml b/.upgradenotes/MDL-74939-2024053010552599.yml
new file mode 100644
index 00000000000..48c3e523f18
--- /dev/null
+++ b/.upgradenotes/MDL-74939-2024053010552599.yml
@@ -0,0 +1,8 @@
+issueNumber: MDL-74939
+notes:
+  core:
+    - message: >-
+        Support for deprecated `<component>\local\views\secondary`
+        block/activity namespace, for overriding secondary navigation, is now
+        entirely removed
+      type: removed
diff --git a/lib/blocklib.php b/lib/blocklib.php
index 662482da01d..b59f6902e72 100644
--- a/lib/blocklib.php
+++ b/lib/blocklib.php
@@ -1726,22 +1726,17 @@ class block_manager {
      * Convenience function to check whether a block is implementing a secondary nav class and return it
      * initialised to the calling function
      *
-     * @todo MDL-74939 Remove support for old 'local\views\secondary' class location
      * @param block_base $block
      * @return \core\navigation\views\secondary
      */
     protected function get_secondarynav(block_base $block): \core\navigation\views\secondary {
         $class = "core_block\\navigation\\views\\secondary";
+
+        // Check whether block defines its own secondary navigation.
         if (class_exists("block_{$block->name()}\\navigation\\views\\secondary")) {
             $class = "block_{$block->name()}\\navigation\\views\\secondary";
-        } else if (class_exists("block_{$block->name()}\\local\\views\\secondary")) {
-            // For backwards compatibility, support the old location for this class (it was in a
-            // 'local' namespace which shouldn't be used for core APIs).
-            debugging("The class block_{$block->name()}\\local\\views\\secondary uses a deprecated " .
-                    "namespace. Please move it to block_{$block->name()}\\navigation\\views\\secondary.",
-                    DEBUG_DEVELOPER);
-            $class = "block_{$block->name()}\\local\\views\\secondary";
         }
+
         $secondarynav = new $class($this->page);
         $secondarynav->initialise();
         return $secondarynav;
diff --git a/lib/db/renamedclasses.php b/lib/db/renamedclasses.php
index afaff2205fc..3a3d1291ba2 100644
--- a/lib/db/renamedclasses.php
+++ b/lib/db/renamedclasses.php
@@ -42,7 +42,6 @@ $renamedclasses = [
     'core_course\\local\\entities\\course_category' => 'core_course\\reportbuilder\\local\\entities\\course_category',
     'core_cohort\\local\\entities\\cohort' => 'core_cohort\\reportbuilder\\local\\entities\\cohort',
     'core_cohort\\local\\entities\\cohort_member' => 'core_cohort\\reportbuilder\\local\\entities\\cohort_member',
-    'core_block\\local\\views\\secondary' => 'core_block\\navigation\\views\\secondary',
     // Since Moodle 4.2.
     'Box\\Spout' => 'OpenSpout',
     // Since Moodle 4.3.
diff --git a/lib/pagelib.php b/lib/pagelib.php
index 1c4d0019509..c0850b6f53a 100644
--- a/lib/pagelib.php
+++ b/lib/pagelib.php
@@ -879,22 +879,15 @@ class moodle_page {
     /**
      * Returns the secondary navigation object
      *
-     * @todo MDL-74939 Remove support for old 'local\views\secondary' class location
      * @return secondary
      */
     protected function magic_get_secondarynav() {
         if ($this->_secondarynav === null) {
             $class = 'core\navigation\views\secondary';
-            // Try and load a custom class first.
+
+            // Check whether activity defines its own secondary navigation.
             if (class_exists("mod_{$this->activityname}\\navigation\\views\\secondary")) {
                 $class = "mod_{$this->activityname}\\navigation\\views\\secondary";
-            } else if (class_exists("mod_{$this->activityname}\\local\\views\\secondary")) {
-                // For backwards compatibility, support the old location for this class (it was in a
-                // 'local' namespace which shouldn't be used for core APIs).
-                debugging("The class mod_{$this->activityname}}\\local\\views\\secondary uses a deprecated " .
-                        "namespace. Please move it to mod_{$this->activityname}\\navigation\\views\\secondary.",
-                        DEBUG_DEVELOPER);
-                $class = "mod_{$this->activityname}\\local\\views\\secondary";
             }
 
             $this->_secondarynav = new $class($this);
diff --git a/mod/assign/db/renamedclasses.php b/mod/assign/db/renamedclasses.php
deleted file mode 100644
index 116e9b6dcdc..00000000000
--- a/mod/assign/db/renamedclasses.php
+++ /dev/null
@@ -1,31 +0,0 @@
-<?php
-// This file is part of Moodle - http://moodle.org/
-//
-// Moodle is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// Moodle is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
-
-/**
- * This file contains mappings for classes that have been renamed.
- *
- * @package    mod_assign
- * @copyright  2021 Catalyst IT Australia Pty Ltd
- * @author     Cameron Ball <cameron@cameron1729.xyz>
- * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
- */
-
-defined('MOODLE_INTERNAL') || die();
-
-$renamedclasses = [
-    // Since Moodle 4.1.
-    'mod_assign\local\views\secondary' => 'mod_assign\navigation\views\secondary',
-];
diff --git a/mod/quiz/db/renamedclasses.php b/mod/quiz/db/renamedclasses.php
index 292493fcab0..7b946ee43e6 100644
--- a/mod/quiz/db/renamedclasses.php
+++ b/mod/quiz/db/renamedclasses.php
@@ -25,8 +25,6 @@
 defined('MOODLE_INTERNAL') || die();
 
 $renamedclasses = [
-    // Since Moodle 4.1.
-    'mod_quiz\local\views\secondary' => 'mod_quiz\navigation\views\secondary',
     // Since Moodle 4.2.
     'mod_quiz_display_options' => 'mod_quiz\question\display_options',
     'qubaids_for_quiz' => 'mod_quiz\question\qubaids_for_quiz',