diff --git a/app/controllers/registrations_controller.rb b/app/controllers/registrations_controller.rb
index 995303a631afb64c000e269746aba1bb2777581a..2be7b72159e9ba62885664350975e40e196cfd85 100644
--- a/app/controllers/registrations_controller.rb
+++ b/app/controllers/registrations_controller.rb
@@ -15,6 +15,7 @@ class RegistrationsController < Devise::RegistrationsController
   layout 'devise'
 
   prepend_before_action :check_captcha, only: :create
+  before_action :ensure_first_name_and_last_name_not_empty, only: :create
   before_action :ensure_destroy_prerequisites_met, only: [:destroy]
   before_action :init_preferred_language, only: :new
   before_action :load_recaptcha, only: :new
@@ -172,6 +173,21 @@ def check_captcha
     render action: 'new'
   end
 
+  def ensure_first_name_and_last_name_not_empty
+    # The key here will be affected by feature flag 'arkose_labs_signup_challenge'
+    # When flag is disabled, the key will be 'user' because #check_captcha will remove 'new_' prefix
+    # When flag is enabled, #check_captcha will be skipped, so the key will have 'new_' prefix
+    first_name = params.dig(resource_name, :first_name) || params.dig("new_#{resource_name}", :first_name)
+    last_name = params.dig(resource_name, :last_name) || params.dig("new_#{resource_name}", :last_name)
+
+    return if first_name.present? && last_name.present?
+
+    resource.errors.add(_('First name'), _("cannot be blank")) if first_name.blank?
+    resource.errors.add(_('Last name'), _("cannot be blank")) if last_name.blank?
+
+    render action: 'new'
+  end
+
   def pending_approval?
     return false unless Gitlab::CurrentSettings.require_admin_approval_after_user_signup
 
diff --git a/locale/gitlab.pot b/locale/gitlab.pot
index 78b870a8266bfcccd7c534b39c8041443d041183..de0aacb2c6699ea6e901115132f68e01b5b865a9 100644
--- a/locale/gitlab.pot
+++ b/locale/gitlab.pot
@@ -47938,6 +47938,9 @@ msgstr ""
 msgid "cannot be associated with both a Group and a Project"
 msgstr ""
 
+msgid "cannot be blank"
+msgstr ""
+
 msgid "cannot be changed"
 msgstr ""
 
diff --git a/spec/controllers/registrations_controller_spec.rb b/spec/controllers/registrations_controller_spec.rb
index 8775f68a5dea8205ad9ecca9c84ac8ce3f377dfa..489461d8876ceeed68ccdd8dbcfda6bc95e4d5ca 100644
--- a/spec/controllers/registrations_controller_spec.rb
+++ b/spec/controllers/registrations_controller_spec.rb
@@ -552,6 +552,39 @@
         end
       end
     end
+
+    context 'when the first or last name is not "present?"' do
+      using RSpec::Parameterized::TableSyntax
+
+      render_views
+
+      shared_examples 'a user without present first name or last name' do
+        it 'renders the form with errors' do
+          subject
+          expect(controller.current_user).to be_nil
+          expect(response).to render_template(:new)
+          expect(response.body).to include(_('name cannot be blank')) # include 'First name' or 'Last name' or both
+        end
+      end
+
+      where(:first_name, :last_name) do
+        nil     | 'last'
+        ''      | 'last'
+        '   '   | 'last'
+        'first' | nil
+        'first' | ''
+        'first' | '   '
+        ''      | ''
+      end
+
+      with_them do
+        before do
+          base_user_params.merge!({ first_name: first_name, last_name: last_name })
+        end
+
+        it_behaves_like 'a user without present first name or last name'
+      end
+    end
   end
 
   describe '#destroy' do