diff --git a/odoo/addons/base/models/ir_model.py b/odoo/addons/base/models/ir_model.py
index 06647266004..5777683d53f 100644
--- a/odoo/addons/base/models/ir_model.py
+++ b/odoo/addons/base/models/ir_model.py
@@ -1370,6 +1370,29 @@ class IrModelSelection(models.Model):
 
     def _process_ondelete(self):
         """ Process the 'ondelete' of the given selection values. """
+        def safe_write(records, fname, value):
+            if not records:
+                return
+            try:
+                with self.env.cr.savepoint():
+                    records.write({fname: value})
+            except Exception:
+                # going through the ORM failed, probably because of an exception
+                # in an override or possibly a constraint.
+                _logger.warning(
+                    "Could not fulfill ondelete action for field %s.%s, "
+                    "attempting ORM bypass...", records._name, fname,
+                )
+                query = sql.SQL("UPDATE {} SET {}=%s WHERE id IN %s").format(
+                    sql.Identifier(records._table),
+                    sql.Identifier(fname),
+                )
+                # if this fails then we're shit out of luck and there's nothing
+                # we can do except fix on a case-by-case basis
+                value = field.convert_to_column(value, records)
+                self.env.cr.execute(query, [value, records._ids])
+                records.invalidate_cache([fname])
+
         for selection in self:
             Model = self.env[selection.field_id.model]
             # The field may exist in database but not in registry. In this case
@@ -1392,10 +1415,10 @@ class IrModelSelection(models.Model):
             elif callable(ondelete):
                 ondelete(selection._get_records())
             elif ondelete == 'set null':
-                selection._get_records().write({field.name: False})
+                safe_write(selection._get_records(), field.name, False)
             elif ondelete == 'set default':
                 value = field.convert_to_write(field.default(Model), Model)
-                selection._get_records().write({field.name: value})
+                safe_write(selection._get_records(), field.name, value)
             elif ondelete == 'cascade':
                 selection._get_records().unlink()
             else:
@@ -2152,13 +2175,12 @@ class IrModelData(models.Model):
         constraints = self.env['ir.model.constraint'].search([('module', 'in', modules.ids)])
         constraints._module_data_uninstall()
 
-        # Remove fields, selections and relations. Note that the selections of
-        # removed fields do not require any "data fix", as their corresponding
-        # column no longer exists. We can therefore completely ignore them. That
-        # is why selections are removed after fields: most selections are
-        # deleted on cascade by their corresponding field.
-        delete(self.env['ir.model.fields'].browse(unique(field_ids)))
+        # If we delete a selection field, and some of its values have ondelete='cascade',
+        # we expect the records with that value to be deleted. If we delete the field first,
+        # the column is dropped and the selection is gone, and thus the records above will not
+        # be deleted.
         delete(self.env['ir.model.fields.selection'].browse(unique(selection_ids)).exists())
+        delete(self.env['ir.model.fields'].browse(unique(field_ids)))
         relations = self.env['ir.model.relation'].search([('module', 'in', modules.ids)])
         relations._module_data_uninstall()
 
diff --git a/odoo/addons/test_new_api/models/test_new_api.py b/odoo/addons/test_new_api/models/test_new_api.py
index 8ff42a51287..8ee4730f18b 100644
--- a/odoo/addons/test_new_api/models/test_new_api.py
+++ b/odoo/addons/test_new_api/models/test_new_api.py
@@ -1152,6 +1152,29 @@ class SelectionNonStored(models.Model):
     ], store=False)
 
 
+class SelectionRequiredForWriteOverride(models.Model):
+    _name = 'test_new_api.model_selection_required_for_write_override'
+    _description = "Model with required selection field for an extension with write override"
+
+    my_selection = fields.Selection([
+        ('foo', "Foo"),
+        ('bar', "Bar"),
+    ], required=True, default='foo')
+
+
+class SelectionRequiredWithWriteOverride(models.Model):
+    _inherit = 'test_new_api.model_selection_required_for_write_override'
+
+    my_selection = fields.Selection(selection_add=[
+        ('divinity', "Divinity: Original Sin 2"),
+    ], ondelete={'divinity': 'set default'})
+
+    def write(self, vals):
+        if 'my_selection' in vals:
+            raise ValueError("No... no no no")
+        return super().write(vals)
+
+
 # Special classes to ensure the correct usage of a shared cache amongst users.
 # See the method test_shared_cache_computed_field
 class SharedCacheComputeParent(models.Model):
diff --git a/odoo/addons/test_new_api/security/ir.model.access.csv b/odoo/addons/test_new_api/security/ir.model.access.csv
index b0e2a0b593b..e3dff81114b 100644
--- a/odoo/addons/test_new_api/security/ir.model.access.csv
+++ b/odoo/addons/test_new_api/security/ir.model.access.csv
@@ -61,6 +61,7 @@ access_test_new_api_monetary_order_line,access_test_new_api_monetary_order_line,
 access_test_new_api_model_selection_base,access_test_new_api_model_selection_base,model_test_new_api_model_selection_base,,1,1,1,1
 access_test_new_api_model_selection_required,access_test_new_api_model_selection_required,model_test_new_api_model_selection_required,,1,1,1,1
 access_test_new_api_model_selection_non_stored,access_test_new_api_model_selection_non_stored,model_test_new_api_model_selection_non_stored,,1,1,1,1
+access_test_new_api_model_selection_required_for_write_override,access_test_new_api_model_selection_required_for_write_override,model_test_new_api_model_selection_required_for_write_override,,1,1,1,1
 access_test_new_api_move,access_test_new_api_move,model_test_new_api_move,,1,1,1,1
 access_test_new_api_move_line,access_test_new_api_move_line,model_test_new_api_move_line,,1,1,1,1
 access_test_new_api_model_shared_cache_compute_parent,access_test_new_api.model_shared_cache_compute_parent,model_test_new_api_model_shared_cache_compute_parent,,1,1,1,1
diff --git a/odoo/addons/test_new_api/tests/test_new_fields.py b/odoo/addons/test_new_api/tests/test_new_fields.py
index ff60190704d..01bae6a6e73 100644
--- a/odoo/addons/test_new_api/tests/test_new_fields.py
+++ b/odoo/addons/test_new_api/tests/test_new_fields.py
@@ -2928,6 +2928,7 @@ class TestSelectionOndelete(common.TransactionCase):
     MODEL_BASE = 'test_new_api.model_selection_base'
     MODEL_REQUIRED = 'test_new_api.model_selection_required'
     MODEL_NONSTORED = 'test_new_api.model_selection_non_stored'
+    MODEL_WRITE_OVERRIDE = 'test_new_api.model_selection_required_for_write_override'
 
     def setUp(self):
         super().setUp()
@@ -3066,6 +3067,16 @@ class TestSelectionOndelete(common.TransactionCase):
         self._unlink_option(self.MODEL_REQUIRED, 'foo')
         self.assertEqual(rec.my_selection, 'foo')
 
+    @mute_logger('odoo.addons.base.models.ir_model')
+    def test_write_override_selection(self):
+        # test that on override to write that raises an error does not prevent the ondelete
+        # policy from executing and cleaning up what needs to be cleaned up
+        rec = self.env[self.MODEL_WRITE_OVERRIDE].create({'my_selection': 'divinity'})
+        self.assertEqual(rec.my_selection, 'divinity')
+
+        self._unlink_option(self.MODEL_WRITE_OVERRIDE, 'divinity')
+        self.assertEqual(rec.my_selection, 'foo')
+
 
 @common.tagged('selection_ondelete_advanced')
 class TestSelectionOndeleteAdvanced(common.TransactionCase):