diff --git a/.forgejo/workflows/phpunit.yml b/.forgejo/workflows/phpunit.yml
index c79e189..2f737d7 100644
--- a/.forgejo/workflows/phpunit.yml
+++ b/.forgejo/workflows/phpunit.yml
@@ -38,7 +38,7 @@ jobs:
           path: |
             ${{ env.WP_CORE_DIR }}
             ${{ env.WP_TESTS_DIR }}
-          key: cache-wordpress-67-3
+          key: cache-wordpress-67-4
 
       - name: Cache Composer
         id: cache-composer-phpunit
@@ -113,4 +113,9 @@ jobs:
       - name: Run Integration tests for EventPrime
         run: cd /workspace/Event-Federation/wordpress-activitypub-event-bridge/ && ./vendor/bin/phpunit --filter=eventprime
         env:
-          PHP_VERSION: ${{ matrix.php-version }}
\ No newline at end of file
+          PHP_VERSION: ${{ matrix.php-version }}
+
+      - name: Run Integration tests for Event Organiser
+        run: cd /workspace/Event-Federation/wordpress-activitypub-event-bridge/ && ./vendor/bin/phpunit --filter=event_organiser
+        env:
+          PHP_VERSION: ${{ matrix.php-version }}
diff --git a/bin/install-wp-tests.sh b/bin/install-wp-tests.sh
index 7cbf282..95fc2e5 100755
--- a/bin/install-wp-tests.sh
+++ b/bin/install-wp-tests.sh
@@ -261,6 +261,7 @@ install_wp_plugins() {
 	install_wp_plugin events-manager "6.6.3"
 	install_wp_plugin wp-event-manager "3.1.45.1"
 	install_wp_plugin wp-event-solution "4.0.14"
+	install_wp_plugin event-organiser "3.12.8"
 	# Mec is not installable via wordpress.org, we use our own mirror.
 	install_wp_plugin_mec
 }
diff --git a/composer.json b/composer.json
index d4c2b0b..36e5525 100644
--- a/composer.json
+++ b/composer.json
@@ -55,11 +55,12 @@
             "@test-wp-event-manager",
             "@test-eventin",
             "@test-modern-events-calendar-lite",
-            "@test-eventprime"
+            "@test-eventprime",
+            "@test-event-organiser"
         ],
         "test-debug": [
             "@prepare-test",
-            "@test-eventprime"
+            "@test-event-organiser"
         ],
         "test-vs-event-list": "phpunit --filter=vs_event_list",
         "test-the-events-calendar": "phpunit --filter=the_events_calendar",
@@ -69,6 +70,7 @@
         "test-eventin": "phpunit --filter=eventin",
         "test-modern-events-calendar-lite": "phpunit --filter=modern_events_calendar_lite",
         "test-eventprime": "phpunit --filter=eventprime",
+        "test-event-organiser": "phpunit --filter=event_organiser",
         "test-all": "phpunit"
     }
 }
diff --git a/includes/activitypub/transformer/class-event-organiser.php b/includes/activitypub/transformer/class-event-organiser.php
new file mode 100644
index 0000000..4d65dfa
--- /dev/null
+++ b/includes/activitypub/transformer/class-event-organiser.php
@@ -0,0 +1,76 @@
+<?php
+/**
+ * ActivityPub Transformer for the plugin Event Organiser.
+ *
+ * @package ActivityPub_Event_Bridge
+ * @license AGPL-3.0-or-later
+ */
+
+namespace ActivityPub_Event_Bridge\Activitypub\Transformer;
+
+// Exit if accessed directly.
+defined( 'ABSPATH' ) || exit; // @codeCoverageIgnore
+
+use Activitypub\Activity\Extended_Object\Place;
+use ActivityPub_Event_Bridge\Activitypub\Transformer\Event;
+
+/**
+ * ActivityPub Transformer for Event Organiser.
+ *
+ * @since 1.0.0
+ */
+final class Event_Organiser extends Event {
+	/**
+	 * Get the end time from the event object.
+	 */
+	protected function get_end_time(): ?string {
+		return eo_get_the_end( 'Y-m-d\TH:i:s\Z', $this->wp_object->ID );
+	}
+
+	/**
+	 * Get the end time from the event object.
+	 */
+	protected function get_start_time(): string {
+		return eo_get_the_start( 'Y-m-d\TH:i:s\Z', $this->wp_object->ID );
+	}
+
+	/**
+	 * Get location from the event object.
+	 */
+	protected function get_location(): ?Place {
+		$venue_id = eo_get_venue( $this->wp_object->ID );
+
+		if ( ! $venue_id ) {
+			return null;
+		}
+
+		$address = eo_get_venue_address( $venue_id );
+
+		$address['name'] = eo_get_venue_name( $this->wp_object->ID );
+
+		$address['streetAddress'] = $address['address'];
+		unset( $address['address'] );
+
+		$address['postalCode'] = $address['postcode'];
+		unset( $address['postcode'] );
+
+		$address['addressRegion'] = $address['state'];
+		unset( $address['state'] );
+
+		$address['addressLocality'] = $address['city'];
+		unset( $address['city'] );
+
+		$address['addressCountry'] = $address['country'];
+		unset( $address['country'] );
+
+		$address['type'] = 'PostalAddress';
+
+		$location = new Place();
+		$location->set_name( eo_get_venue_name( $this->wp_object->ID ) );
+		$location->set_latitude( eo_get_venue_lat( $this->wp_object->ID ) );
+		$location->set_longitude( eo_get_venue_lng( $this->wp_object->ID ) );
+		$location->set_address( $address );
+
+		return $address;
+	}
+}
diff --git a/includes/class-setup.php b/includes/class-setup.php
index 3b5ef0b..b99eda5 100644
--- a/includes/class-setup.php
+++ b/includes/class-setup.php
@@ -133,6 +133,7 @@ class Setup {
 		'\ActivityPub_Event_Bridge\Plugins\Eventin',
 		'\ActivityPub_Event_Bridge\Plugins\Modern_Events_Calendar_Lite',
 		'\ActivityPub_Event_Bridge\Plugins\EventPrime',
+		'\ActivityPub_Event_Bridge\Plugins\Event_Organiser',
 	);
 
 	/**
diff --git a/includes/plugins/class-event-organiser.php b/includes/plugins/class-event-organiser.php
new file mode 100644
index 0000000..d418bba
--- /dev/null
+++ b/includes/plugins/class-event-organiser.php
@@ -0,0 +1,69 @@
+<?php
+/**
+ * Event Organiser.
+ *
+ * Defines all the necessary meta information for the Event Organiser plugin.
+ *
+ * @link    https://wordpress.org/plugins/event-organiser/
+ * @package ActivityPub_Event_Bridge
+ * @since   1.0.0
+ */
+
+namespace ActivityPub_Event_Bridge\Plugins;
+
+// Exit if accessed directly.
+defined( 'ABSPATH' ) || exit; // @codeCoverageIgnore
+
+/**
+ * Interface for a supported event plugin.
+ *
+ * This interface defines which information is necessary for a supported event plugin.
+ *
+ * @since 1.0.0
+ */
+final class Event_Organiser extends Event_Plugin {
+	/**
+	 * Returns the full plugin file.
+	 *
+	 * @return string
+	 */
+	public static function get_plugin_file(): string {
+		return 'event-organiser/event-organiser.php';
+	}
+
+	/**
+	 * Returns the event post type of the plugin.
+	 *
+	 * @return string
+	 */
+	public static function get_post_type(): string {
+		return 'event';
+	}
+
+	/**
+	 * Returns the IDs of the admin pages of the plugin.
+	 *
+	 * @return array The settings page urls.
+	 */
+	public static function get_settings_pages(): array {
+		return array( 'event-organiser' );
+	}
+
+	/**
+	 * Returns the ActivityPub transformer class.
+	 *
+	 * @return string
+	 */
+	public static function get_activitypub_transformer_class_name(): string {
+		return 'Event_Organiser';
+	}
+
+	/**
+	 * Returns the taxonomy used for the plugin's event categories.
+	 *
+	 * @return string
+	 */
+	public static function get_event_category_taxonomy(): string {
+		return 'event-category';
+	}
+}
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index fef1717..6c3af80 100755
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -74,6 +74,9 @@ function _manually_load_plugin() {
 		case 'eventprime':
 			$plugin_file = 'eventprime-event-calendar-management/event-prime.php';
 			break;
+		case 'event-organiser':
+			$plugin_file = 'event-organiser/event-organiser.php';
+			break;
 	}
 
 	if ( $plugin_file ) {
@@ -100,6 +103,11 @@ function _manually_load_plugin() {
 		$mec_factory->install();
 	}
 
+	if ( 'event-organiser' === $activitypub_event_bridge_integration_filter ) {
+		require_once $plugin_dir . 'event-organiser/includes/event-organiser-install.php';
+		eventorganiser_install();
+	}
+
 	// At last manually load our WordPress plugin.
 	require dirname( __DIR__ ) . '/activitypub-event-bridge.php';
 }
diff --git a/tests/test-class-plugin-event-organiser.php b/tests/test-class-plugin-event-organiser.php
new file mode 100644
index 0000000..a918487
--- /dev/null
+++ b/tests/test-class-plugin-event-organiser.php
@@ -0,0 +1,104 @@
+<?php
+/**
+ * Test class for the integration of the Event Organiser.
+ *
+ * @package ActivityPub_Event_Bridge
+ */
+
+/**
+ * Sample test case.
+ */
+class Test_Event_Organiser extends WP_UnitTestCase {
+	/**
+	 * Override the setup function, so that tests don't run if the Events Calendar is not active.
+	 */
+	public function set_up() {
+		parent::set_up();
+
+		if ( ! function_exists( 'eo_get_events' ) ) {
+			self::markTestSkipped( 'Event Organiser plugin is not active.' );
+		}
+
+		// Mock the plugin activation.
+		GatherPress\Core\Setup::get_instance()->activate_gatherpress_plugin( false );
+
+		// Make sure that ActivityPub support is enabled for The Events Calendar.
+		$aec = \ActivityPub_Event_Bridge\Setup::get_instance();
+		$aec->activate_activitypub_support_for_active_event_plugins();
+
+		// Delete all posts afterwards.
+		_delete_all_posts();
+	}
+
+	/**
+	 * Test that the right transformer gets applied.
+	 */
+	public function test_transformer_class() {
+		// We only test for one event plugin being active at the same time,
+		// even though we support multiple onces in theory.
+		// But testing all combinations is beyond scope.
+		$active_event_plugins = \ActivityPub_Event_Bridge\Setup::get_instance()->get_active_event_plugins();
+		$this->assertEquals( 1, count( $active_event_plugins ) );
+
+		// Enable ActivityPub support for the event plugin.
+		$this->assertContains( 'gatherpress_event', get_option( 'activitypub_support_post_types' ) );
+
+		// Mock GatherPress Event.
+		$post_id = wp_insert_post(
+			array(
+				'post_title'   => 'Unit Test Event',
+				'post_type'    => 'gatherpress_event',
+				'post_content' => 'Unit Test description.',
+				'post_status'  => 'publish',
+			)
+		);
+		$event   = new \GatherPress\Core\Event( $post_id );
+		$params  = array(
+			'datetime_start' => '+10 days 15:00:00',
+			'datetime_end'   => '+10 days 16:00:00',
+			'timezone'       => 'America/New_York',
+		);
+
+		$event->save_datetimes( $params );
+
+		// Call the transformer Factory.
+		$transformer = \Activitypub\Transformer\Factory::get_transformer( $event->event );
+
+		// Check that we got the right transformer.
+		$this->assertInstanceOf( \ActivityPub_Event_Bridge\Activitypub\Transformer\GatherPress::class, $transformer );
+	}
+
+	/**
+	 * Test transformation to ActivityPUb for basic event.
+	 */
+	public function test_transform_of_basic_event() {
+		// Mock GatherPress Event.
+		$post_id = wp_insert_post(
+			array(
+				'post_title'   => 'Unit Test Event',
+				'post_type'    => 'gatherpress_event',
+				'post_content' => 'Unit Test description.',
+				'post_status'  => 'publish',
+			)
+		);
+		$event   = new \GatherPress\Core\Event( $post_id );
+		$params  = array(
+			'datetime_start' => '+10 days 15:00:00',
+			'datetime_end'   => '+10 days 16:00:00',
+			'timezone'       => 'America/New_York',
+		);
+		$event->save_datetimes( $params );
+
+		// Call the transformer Factory.
+		$event_array = \Activitypub\Transformer\Factory::get_transformer( $event->event )->to_object()->to_array();
+
+		// Check that the event ActivityStreams representation contains everything as expected.
+		$this->assertEquals( 'Event', $event_array['type'] );
+		$this->assertEquals( 'Unit Test Event', $event_array['name'] );
+		$this->assertEquals( 'Unit Test description.', wp_strip_all_tags( $event_array['content'] ) );
+		$this->assertEquals( gmdate( 'Y-m-d', strtotime( '+10 days 15:00:00' ) ) . 'T15:00:00Z', $event_array['startTime'] );
+		$this->assertEquals( gmdate( 'Y-m-d', strtotime( '+10 days 16:00:00' ) ) . 'T16:00:00Z', $event_array['endTime'] );
+		$this->assertEquals( 'external', $event_array['joinMode'] );
+		$this->assertArrayNotHasKey( 'location', $event_array );
+	}
+}