diff --git a/app/controllers/admin/notifications_controller.rb b/app/controllers/admin/notifications_controller.rb
index 66aff8043..b81152eb1 100644
--- a/app/controllers/admin/notifications_controller.rb
+++ b/app/controllers/admin/notifications_controller.rb
@@ -3,7 +3,7 @@
 class Admin::NotificationsController < AdminController
   def index
     markdown_parser = Redcarpet::Markdown.new(CustomMarkdownRenderer)
-    @published_notification = Notification.published.first
+    @published_notification = Notification.currently_active.first
     if @published_notification
       @published_notification_message = markdown_parser.render(@published_notification[:notification_message])
     end
@@ -22,9 +22,7 @@ def show
   end
 
   def create
-    @notification = Notification.new(summary: notification_params[:summary],
-                                     notification_message: notification_params[:notification_message],
-                                     user: current_user['email'], published: true, published_at: Time.zone.now)
+    @notification = create_notifications
     Notification.transaction do
       if @notification.save
         flash[:success] = 'Notification created successfully.'
@@ -55,6 +53,23 @@ def unpublish
   private
 
   def notification_params
-    params.require(:notification).permit(:summary, :notification_message)
+    params.require(:notification).permit(:summary, :notification_message, :stop_datetime)
+  end
+
+  def create_notifications
+    Notification.new(summary: notification_params[:summary],
+                     notification_message: notification_params[:notification_message],
+                     user: current_user['email'],
+                     published: true,
+                     published_at: Time.zone.now,
+                     stop_datetime: parsed_stop_datetime)
+  end
+
+  def parsed_stop_datetime
+    return nil if notification_params[:stop_datetime].blank?
+
+    Time.use_zone('Europe/London') do
+      Time.zone.parse(notification_params[:stop_datetime])
+    end
   end
 end
diff --git a/app/controllers/v1/notifications_controller.rb b/app/controllers/v1/notifications_controller.rb
index 07ff88a6e..2ea5d980e 100644
--- a/app/controllers/v1/notifications_controller.rb
+++ b/app/controllers/v1/notifications_controller.rb
@@ -2,6 +2,7 @@
 
 class V1::NotificationsController < ApiController
   def index
+    Notification.expire_past_due!
     markdown_parser = Redcarpet::Markdown.new(CustomMarkdownRenderer)
     notifications = Notification.published.first
     notifications[:notification_message] = markdown_parser.render(notifications[:notification_message]) if notifications
diff --git a/app/models/notification.rb b/app/models/notification.rb
index b24979d60..80941e2db 100644
--- a/app/models/notification.rb
+++ b/app/models/notification.rb
@@ -1,9 +1,14 @@
 class Notification < ApplicationRecord
   validates :summary, :notification_message, presence: true
+  validate :stop_datetime_in_future
 
   before_save :ensure_single_published_notification
 
   scope :published, -> { where(published: true) }
+  scope :currently_active, lambda {
+    where(published: true)
+      .where('stop_datetime IS NULL OR stop_datetime > ?', Time.current)
+  }
 
   def unpublish!
     self.published = false
@@ -11,6 +16,15 @@ def unpublish!
     save!
   end
 
+  def self.expire_past_due!
+    expired = where('stop_datetime < ? AND published = ?', Time.current, true)
+    # We use update_all for performance to expire records in a single
+    # SQL query, bypassing validations for speed on every API request.
+    # rubocop:disable Rails/SkipsModelValidations
+    expired.update_all(published: false, unpublished_at: Time.zone.now)
+    # rubocop:enable Rails/SkipsModelValidations
+  end
+
   private
 
   def ensure_single_published_notification
@@ -18,4 +32,10 @@ def ensure_single_published_notification
 
     Notification.where.not(id: id).where(published: true).find_each(&:unpublish!)
   end
+
+  def stop_datetime_in_future
+    return unless stop_datetime.present? && stop_datetime < Time.current
+
+    errors.add(:stop_datetime, 'must be in the future')
+  end
 end
diff --git a/app/views/admin/notifications/index.html.haml b/app/views/admin/notifications/index.html.haml
index d369a9178..7215311a3 100644
--- a/app/views/admin/notifications/index.html.haml
+++ b/app/views/admin/notifications/index.html.haml
@@ -36,9 +36,11 @@
             %th.govuk-table__header Header
             %th.govuk-table__header Published
             %th.govuk-table__header Unpublished
+            %th.govuk-table__header Date time to Unpublish
         %tbody.govuk-table__body
           - @notifications.each do |notification|
             %tr.govuk-table__row
               %td.govuk-table__cell= link_to notification.summary, admin_notification_path(notification.id)
               %td.govuk-table__cell= notification.published_at
               %td.govuk-table__cell= notification.unpublished_at
+              %td.govuk-table__cell= notification.stop_datetime
diff --git a/app/views/admin/notifications/new.html.haml b/app/views/admin/notifications/new.html.haml
index 21b0652a5..e771a2cae 100644
--- a/app/views/admin/notifications/new.html.haml
+++ b/app/views/admin/notifications/new.html.haml
@@ -1,15 +1,39 @@
 .govuk-grid-row
   .govuk-grid-column-two-thirds
     = link_to 'Back', admin_notifications_path, { class: 'govuk-back-link govuk-!-margin-bottom-5', title: 'Back to notifications' }
-
     = simple_form_for [:admin, @notification] do |form|
       %fieldset.govuk-fieldset
         %legend.govuk-fieldset__legend.govuk-fieldset__legend--xl
           %h1.govuk-fieldset__heading
             Create a new notification
 
-        = form.input :summary, hide_optional: true, input_html: { value: @published_notification&.summary }
-        = form.input :notification_message, label: 'Notification message', hide_optional: true, wrapper: :govuk_textarea_wrapper, input_html: { rows: '10', value: @published_notification&.notification_message }
+          = form.input :summary, 
+            hide_optional: true, 
+            input_html: { value: @notification.summary || @published_notification&.summary }
+
+          = form.input :notification_message, 
+            label: 'Notification message', 
+            hide_optional: true, 
+            wrapper: :govuk_textarea_wrapper, 
+            input_html: { rows: '10', value: @notification.notification_message || @published_notification&.notification_message }
+
+          .govuk-form-group{class: ("govuk-form-group--error" if @notification.errors[:stop_datetime].any?)}
+            %label.govuk-label{ for: "notification_stop_datetime" }
+              Unpublish on
+            
+            - if @notification.errors[:stop_datetime].any?
+              %span.govuk-error-message
+                %span.govuk-visually-hidden Error:
+                = @notification.errors[:stop_datetime].join(', ')
+
+            - current_date = @notification.stop_datetime || @published_notification&.stop_datetime
+            - current_date_london = current_date&.in_time_zone('Europe/London')
+            = form.datetime_local_field :stop_datetime, 
+              class: "govuk-input", 
+              value: current_date_london&.strftime("%Y-%m-%dT%H:%M")
+          %button.govuk-button.govuk-button--secondary{ type: "button", onclick: "document.getElementById('notification_stop_datetime').value = ''", class: "govuk-!-margin-top-1" }
+            Clear date
+
         %button#markdown-preview-btn{type: "button", class: 'govuk-button'} Preview
         = form.button :submit, value: 'Publish Notification', data: { disable_with: "Publish Notification" }
 
diff --git a/db/migrate/20260302_add_stop_datetime_to_notifications.rb b/db/migrate/20260302_add_stop_datetime_to_notifications.rb
new file mode 100644
index 000000000..09d4e3a2b
--- /dev/null
+++ b/db/migrate/20260302_add_stop_datetime_to_notifications.rb
@@ -0,0 +1,6 @@
+class AddStopDatetimeToNotifications < ActiveRecord::Migration[6.0]
+  def change
+    add_column :notifications, :stop_datetime, :datetime, null: true
+    add_index :notifications, :stop_datetime
+  end
+end
\ No newline at end of file
diff --git a/db/schema.rb b/db/schema.rb
index d4bca3270..b1e9143f9 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -161,10 +161,12 @@
     t.text "notification_message"
     t.boolean "published", default: false
     t.datetime "published_at"
+    t.datetime "stop_datetime", precision: nil
     t.text "summary", null: false
     t.datetime "unpublished_at"
     t.string "user"
     t.index ["published"], name: "index_notifications_on_published"
+    t.index ["stop_datetime"], name: "index_notifications_on_stop_datetime"
   end
 
   create_table "release_notes", id: :uuid, default: -> { "gen_random_uuid()" }, force: :cascade do |t|
diff --git a/spec/factories/notifications.rb b/spec/factories/notifications.rb
index 465cddb96..d4d85a3b6 100644
--- a/spec/factories/notifications.rb
+++ b/spec/factories/notifications.rb
@@ -4,6 +4,7 @@
     notification_message { 'Wear sunscreen' }
     published { false }
     published_at { Time.zone.now }
+    stop_datetime { nil }
     unpublished_at { nil }
     user { 'testy.mctestface@example.com' }
   end
diff --git a/spec/models/notification_spec.rb b/spec/models/notification_spec.rb
index c22154658..b9ada794e 100644
--- a/spec/models/notification_spec.rb
+++ b/spec/models/notification_spec.rb
@@ -5,6 +5,56 @@
     subject { create(:notification, published: true) }
     it { is_expected.to validate_presence_of(:summary) }
     it { is_expected.to validate_presence_of(:notification_message) }
+
+    it 'is invalid if stop_datetime is in the past' do
+      notification = build(:notification, stop_datetime: 1.day.ago)
+      expect(notification).not_to be_valid
+      expect(notification.errors[:stop_datetime]).to include('must be in the future')
+    end
+
+    it 'is valid if stop_datetime is in the future' do
+      notification = build(:notification, stop_datetime: 1.day.from_now)
+      expect(notification).to be_valid
+    end
+
+    it 'is valid if stop_datetime is nil' do
+      notification = build(:notification, stop_datetime: nil)
+      expect(notification).to be_valid
+    end
+  end
+
+  describe 'scopes' do
+    describe '.currently_active' do
+      it 'includes published notifications with future stop dates' do
+        active = create(:notification, published: true, stop_datetime: 1.hour.from_now)
+        expect(Notification.currently_active).to include(active)
+      end
+
+      it 'includes published notifications with no stop date' do
+        permanent = create(:notification, published: true, stop_datetime: nil)
+        expect(Notification.currently_active).to include(permanent)
+      end
+
+      it 'excludes notifications that have passed their stop date' do
+        # Use save(validate: false) to simulate an old record that was valid when created
+        expired = build(:notification, published: true, stop_datetime: 1.hour.ago)
+        expired.save(validate: false)
+        expect(Notification.currently_active).not_to include(expired)
+      end
+    end
+  end
+
+  describe '.expire_past_due!' do
+    it 'updates all past-due notifications to be unpublished' do
+      expired = build(:notification, published: true, stop_datetime: 1.minute.ago)
+      expired.save(validate: false)
+
+      Notification.expire_past_due!
+
+      expired.reload
+      expect(expired.published).to be false
+      expect(expired.unpublished_at).to be_within(1.second).of(Time.zone.now)
+    end
   end
 
   describe '#unpublish!' do
diff --git a/spec/requests/admin/notifications_spec.rb b/spec/requests/admin/notifications_spec.rb
index 7ac896f66..a4de6dbd8 100644
--- a/spec/requests/admin/notifications_spec.rb
+++ b/spec/requests/admin/notifications_spec.rb
@@ -9,6 +9,33 @@
     get '/auth/google_oauth2/callback'
   end
 
+  describe '#create' do
+    around do |example|
+      travel_to(Time.utc(2026, 4, 20, 12, 0, 0)) { example.run }
+    end
+
+    it 'stores stop_datetime as Europ/London local time converted to UTC' do
+      london_input = '2026-04-20T14:15:00' # 2:15 PM London time on April 20, 2026
+
+      expect do
+        post admin_notifications_path, params: {
+          notification: {
+            summary: 'Test Notification',
+            notification_message: 'This is a test notification.',
+            stop_datetime: london_input
+          }
+        }
+      end.to change(Notification, :count).by(1)
+
+      notification = Notification.order(published_at: :desc).first
+
+      expected_time = ActiveSupport::TimeZone['Europe/London'].parse(london_input)
+
+      expect(notification.stop_datetime).to eq(expected_time)
+      expect(notification.stop_datetime.utc).to eq(expected_time.utc)
+    end
+  end
+
   describe '#preview' do
     it 'renders the Markdown content as HTML' do
       markdown_content = '**Bold Text**'
diff --git a/spec/requests/v1/notifications_spec.rb b/spec/requests/v1/notifications_spec.rb
index d7094e711..6873367eb 100644
--- a/spec/requests/v1/notifications_spec.rb
+++ b/spec/requests/v1/notifications_spec.rb
@@ -3,6 +3,13 @@
 RSpec.describe '/v1' do
   let(:user) { FactoryBot.create(:user) }
 
+  let(:auth_headers) do
+    {
+      'HTTP_AUTHORIZATION' => ActionController::HttpAuthentication::Basic.encode_credentials('dxw', 'sdfhg'),
+      'X-Auth-Id' => JWT.encode(user.auth_id, 'test')
+    }
+  end
+
   describe 'GET /v1/notifications' do
     it 'returns 401 if authentication needed and not provided' do
       ClimateControl.modify API_PASSWORD: 'sdfhg' do
@@ -17,25 +24,22 @@
 
     it 'returns ok if authentication needed and provided' do
       ClimateControl.modify API_PASSWORD: 'sdfhg' do
-        get '/v1/notifications', params: {}, headers: {
-          HTTP_AUTHORIZATION: ActionController::HttpAuthentication::Basic.encode_credentials('dxw', 'sdfhg'),
-          'X-Auth-Id' => JWT.encode(user.auth_id, 'test')
-        }
+        get '/v1/notifications', params: {}, headers: auth_headers
         expect(response).to be_successful
       end
     end
 
     it 'returns the details of the current published notification' do
       FactoryBot.create(:notification, published: true, summary: 'Testy McTestface',
-notification_message: 'The answer is 42')
+                        notification_message: 'The answer is 42')
 
-      get '/v1/notifications', headers: { 'X-Auth-Id' => JWT.encode(user.auth_id, 'test') }
+      ClimateControl.modify API_PASSWORD: 'sdfhg' do
+        get '/v1/notifications', headers: auth_headers
 
-      expect(response).to be_successful
-      expect(json['data'])
-        .to have_attribute(:summary)
-      expect(json['data'])
-        .to have_attribute(:notification_message)
+        expect(response).to be_successful
+        expect(json['data']).to have_attribute(:summary).with_value('Testy McTestface')
+        expect(json['data']).to have_attribute(:notification_message)
+      end
     end
   end
 end