diff --git a/.upgradenotes/MDL-83440-2024101111263005.yml b/.upgradenotes/MDL-83440-2024101111263005.yml
new file mode 100644
index 00000000000..1cf9a36e08e
--- /dev/null
+++ b/.upgradenotes/MDL-83440-2024101111263005.yml
@@ -0,0 +1,8 @@
+issueNumber: MDL-83440
+notes:
+  mod_assign:
+    - message: >-
+        Assign sub-plugins have a new method assign_plugin::settings_validation
+        which can be overridden to validate the data when the assignments form
+        is saved.
+      type: improved
diff --git a/mod/assign/assignmentplugin.php b/mod/assign/assignmentplugin.php
index 2fc74e4ffaf..a1c126e2194 100644
--- a/mod/assign/assignmentplugin.php
+++ b/mod/assign/assignmentplugin.php
@@ -107,6 +107,20 @@ abstract class assign_plugin {
         return;
     }
 
+    /**
+     * This method is called when the mod_assign_mod_form is submitted.
+     *
+     * It is an opportunity to validate the settings form fields added by {@see get_settings()}.
+     *
+     * @param array $data as passed to mod_assign_mod_form::validation().
+     * @param array $files as passed to mod_assign_mod_form::validation().
+     * @return array and validation errors that should be displayed.
+     *      This is array_merged with any other validation errors from the form.
+     */
+    public function settings_validation(array $data, array $files): array {
+        return [];
+    }
+
     /**
      * The assignment subtype is responsible for saving it's own settings as the database table for the
      * standard type cannot be modified.
diff --git a/mod/assign/locallib.php b/mod/assign/locallib.php
index d00b198eb0a..d3a1674388d 100644
--- a/mod/assign/locallib.php
+++ b/mod/assign/locallib.php
@@ -150,10 +150,10 @@ class assign {
      */
     private $cache;
 
-    /** @var array list of the installed submission plugins */
+    /** @var assign_submission_plugin[] list of the installed submission plugins */
     private $submissionplugins;
 
-    /** @var array list of the installed feedback plugins */
+    /** @var assign_feedback_plugin[] list of the installed feedback plugins */
     private $feedbackplugins;
 
     /** @var string action to be used to return to this page
@@ -1746,6 +1746,31 @@ class assign {
         }
     }
 
+    /**
+     * Allow each plugin to validiate the data from the assignments settings form.
+     *
+     * @param array $data as passed to mod_assign_mod_form::validation().
+     * @param array $files as passed to mod_assign_mod_form::validation().
+     * @return array and validation errors that should be displayed.
+     */
+    public function plugin_settings_validation(array $data, array $files): array {
+        $errors = [];
+
+        foreach ($this->submissionplugins as $plugin) {
+            if ($plugin->is_visible()) {
+                $errors = array_merge($errors, $plugin->settings_validation($data, $files));
+            }
+        }
+
+        foreach ($this->feedbackplugins as $plugin) {
+            if ($plugin->is_visible()) {
+                $errors = array_merge($errors, $plugin->settings_validation($data, $files));
+            }
+        }
+
+        return $errors;
+    }
+
     /**
      * Get the name of the current module.
      *
diff --git a/mod/assign/mod_form.php b/mod/assign/mod_form.php
index 475f929639e..48365ab997d 100644
--- a/mod/assign/mod_form.php
+++ b/mod/assign/mod_form.php
@@ -42,7 +42,7 @@ class mod_assign_mod_form extends moodleform_mod {
      * @return void
      */
     public function definition() {
-        global $CFG, $COURSE, $DB;
+        global $CFG, $COURSE;
         $mform = $this->_form;
 
         $mform->addElement('header', 'general', get_string('general', 'form'));
@@ -73,19 +73,7 @@ class mod_assign_mod_form extends moodleform_mod {
         $mform->addElement('advcheckbox', 'submissionattachments', get_string('submissionattachments', 'assign'));
         $mform->addHelpButton('submissionattachments', 'submissionattachments', 'assign');
 
-        $ctx = null;
-        if ($this->current && $this->current->coursemodule) {
-            $cm = get_coursemodule_from_instance('assign', $this->current->id, 0, false, MUST_EXIST);
-            $ctx = context_module::instance($cm->id);
-        }
-        $assignment = new assign($ctx, null, null);
-        if ($this->current && $this->current->course) {
-            if (!$ctx) {
-                $ctx = context_course::instance($this->current->course);
-            }
-            $course = $DB->get_record('course', array('id'=>$this->current->course), '*', MUST_EXIST);
-            $assignment->set_course($course);
-        }
+        [$assignment] = $this->get_assign();
 
         $mform->addElement('header', 'availability', get_string('availability', 'assign'));
         $mform->setExpanded('availability', true);
@@ -287,6 +275,9 @@ class mod_assign_mod_form extends moodleform_mod {
             $errors['attemptreopenmethod'] = get_string('reopenuntilpassincompatiblewithblindmarking', 'assign');
         }
 
+        [$assignment] = $this->get_assign();
+        $errors = array_merge($errors, $assignment->plugin_settings_validation($data, $files));
+
         return $errors;
     }
 
@@ -296,21 +287,7 @@ class mod_assign_mod_form extends moodleform_mod {
      * @param array $defaultvalues
      */
     public function data_preprocessing(&$defaultvalues) {
-        global $DB;
-
-        $ctx = null;
-        if ($this->current && $this->current->coursemodule) {
-            $cm = get_coursemodule_from_instance('assign', $this->current->id, 0, false, MUST_EXIST);
-            $ctx = context_module::instance($cm->id);
-        }
-        $assignment = new assign($ctx, null, null);
-        if ($this->current && $this->current->course) {
-            if (!$ctx) {
-                $ctx = context_course::instance($this->current->course);
-            }
-            $course = $DB->get_record('course', array('id'=>$this->current->course), '*', MUST_EXIST);
-            $assignment->set_course($course);
-        }
+        [$assignment, $ctx] = $this->get_assign();
 
         $draftitemid = file_get_submitted_draft_itemid('introattachments');
         file_prepare_draft_area($draftitemid, $ctx->id, 'mod_assign', ASSIGN_INTROATTACHMENT_FILEAREA,
@@ -406,4 +383,30 @@ class mod_assign_mod_form extends moodleform_mod {
             }
         }
     }
+
+    /**
+     * Get a relevant assign instance for this form, and the context.
+     *
+     * If we are editing an existing assign, it is that assignment and context, otherwise it is for the course context.
+     *
+     * @return array [$assignment, $ctx] the assignment object and the context.
+     */
+    protected function get_assign(): array {
+        global $DB;
+
+        $ctx = null;
+        if ($this->current && $this->current->coursemodule) {
+            $cm = get_coursemodule_from_instance('assign', $this->current->id, 0, false, MUST_EXIST);
+            $ctx = context_module::instance($cm->id);
+        }
+        $assignment = new assign($ctx, null, null);
+        if ($this->current && $this->current->course) {
+            if (!$ctx) {
+                $ctx = context_course::instance($this->current->course);
+            }
+            $course = $DB->get_record('course', ['id' => $this->current->course], '*', MUST_EXIST);
+            $assignment->set_course($course);
+        }
+        return [$assignment, $ctx];
+    }
 }