diff --git a/includes/class-newspack.php b/includes/class-newspack.php
index a98fcee997..9f494fe7fc 100644
--- a/includes/class-newspack.php
+++ b/includes/class-newspack.php
@@ -82,6 +82,7 @@ private function includes() {
 		include_once NEWSPACK_ABSPATH . 'includes/data-events/class-webhooks.php';
 		include_once NEWSPACK_ABSPATH . 'includes/data-events/class-api.php';
 		include_once NEWSPACK_ABSPATH . 'includes/data-events/listeners.php';
+		include_once NEWSPACK_ABSPATH . 'includes/data-events/connectors/class-mailchimp.php';
 		include_once NEWSPACK_ABSPATH . 'includes/class-api.php';
 		include_once NEWSPACK_ABSPATH . 'includes/class-profile.php';
 		include_once NEWSPACK_ABSPATH . 'includes/analytics/class-analytics.php';
diff --git a/includes/data-events/connectors/class-mailchimp.php b/includes/data-events/connectors/class-mailchimp.php
new file mode 100644
index 0000000000..7b54d60547
--- /dev/null
+++ b/includes/data-events/connectors/class-mailchimp.php
@@ -0,0 +1,234 @@
+<?php
+/**
+ * Newspack Data Events Mailchimp Connector
+ *
+ * @package Newspack
+ */
+
+namespace Newspack\Data_Events\Connectors;
+
+use \Newspack\Data_Events;
+use \Newspack\Mailchimp_API;
+use \Newspack\Newspack_Newsletters;
+use \Newspack\Reader_Activation;
+use \Newspack\WooCommerce_Connection;
+use \Newspack\Donations;
+
+defined( 'ABSPATH' ) || exit;
+
+/**
+ * Main Class.
+ */
+class Mailchimp {
+	/**
+	 * Constructor.
+	 */
+	public function __construct() {
+		if (
+			defined( 'NEWSPACK_DATA_EVENTS_MAILCHIMP' ) && NEWSPACK_DATA_EVENTS_MAILCHIMP &&
+			Reader_Activation::is_enabled() &&
+			true === Reader_Activation::get_setting( 'sync_esp' )
+		) {
+			Data_Events::register_handler( [ __CLASS__, 'reader_registered' ], 'reader_registered' );
+			Data_Events::register_handler( [ __CLASS__, 'donation_new' ], 'donation_new' );
+			Data_Events::register_handler( [ __CLASS__, 'donation_subscription_new' ], 'donation_subscription_new' );
+		}
+	}
+
+	/**
+	 * Get audience ID.
+	 *
+	 * @return string|bool Audience ID or false if not set.
+	 */
+	private static function get_audience_id() {
+		/** TODO: UI for handling Mailchimp's master list in RAS. */
+		$audience_id = Reader_Activation::get_setting( 'mailchimp_audience_id' );
+		/** Attempt to use list ID from "Mailchimp for WooCommerce" */
+		if ( ! $audience_id && function_exists( 'mailchimp_get_list_id' ) ) {
+			$audience_id = mailchimp_get_list_id();
+		}
+		return ! empty( $audience_id ) ? $audience_id : false;
+	}
+
+	/**
+	 * Get merge field type.
+	 *
+	 * @param mixed $value Value to check.
+	 *
+	 * @return string Merge field type.
+	 */
+	private static function get_merge_field_type( $value ) {
+		if ( is_numeric( $value ) ) {
+			return 'number';
+		}
+		if ( is_bool( $value ) ) {
+			return 'boolean';
+		}
+		return 'text';
+	}
+
+	/**
+	 * Get merge fields given data.
+	 *
+	 * @param string $audience_id Audience ID.
+	 * @param array  $data        Data to check.
+	 *
+	 * @return array Merge fields.
+	 */
+	private static function get_merge_fields( $audience_id, $data ) {
+		$merge_fields       = [];
+		$fields_option_name = sprintf( 'newspack_data_mailchimp_%s_fields', $audience_id );
+
+		// Strip arrays.
+		$data = array_filter(
+			$data,
+			function( $value ) {
+				return ! is_array( $value );
+			}
+		);
+
+		// Get and match existing merge fields.
+		$fields_ids      = \get_option( $fields_option_name, [] );
+		$existing_fields = Mailchimp_API::get( "lists/$audience_id/merge-fields?count=1000" );
+		foreach ( $existing_fields['merge_fields'] as $field ) {
+			$field_name = '';
+			if ( isset( $fields_ids[ $field['merge_id'] ] ) ) {
+				// Match locally stored merge field ID.
+				$field_name = $fields_ids[ $field['merge_id'] ];
+			} elseif ( isset( $data[ $field['name'] ] ) ) {
+				// Match by merge field name.
+				$field_name                       = $field['name'];
+				$fields_ids[ $field['merge_id'] ] = $field_name;
+			}
+			// If field name is found, add it to the payload.
+			if ( ! empty( $field_name ) && isset( $data[ $field_name ] ) ) {
+				$merge_fields[ $field['tag'] ] = $data[ $field_name ];
+				unset( $data[ $field_name ] );
+			}
+		}
+
+		// Create remaining fields.
+		$remaining_fields = array_keys( $data );
+		foreach ( $remaining_fields as $field_name ) {
+			$created_field                            = Mailchimp_API::post(
+				"lists/$audience_id/merge-fields",
+				[
+					'name' => $field_name,
+					'type' => self::get_merge_field_type( $data[ $field_name ] ),
+				]
+			);
+			$merge_fields[ $created_field['tag'] ]    = $data[ $field_name ];
+			$fields_ids[ $created_field['merge_id'] ] = $field_name;
+		}
+
+		// Store fields IDs for future use.
+		\update_option( $fields_option_name, $fields_ids );
+		return $merge_fields;
+	}
+
+	/**
+	 * Update a Mailchimp contact
+	 *
+	 * @param string $email Email address.
+	 * @param array  $data  Data to update.
+	 */
+	private static function put( $email, $data = [] ) {
+		$audience_id = self::get_audience_id();
+		if ( ! $audience_id ) {
+			return;
+		}
+		$hash    = md5( strtolower( $email ) );
+		$payload = [
+			'email_address' => $email,
+			'status_if_new' => 'transactional',
+		];
+
+		$merge_fields = self::get_merge_fields( $audience_id, $data );
+		if ( ! empty( $merge_fields ) ) {
+			$payload['merge_fields'] = $merge_fields;
+		}
+
+		// Upsert the contact.
+		Mailchimp_API::put(
+			"lists/$audience_id/members/$hash",
+			$payload
+		);
+	}
+
+	/**
+	 * Handle a reader registering.
+	 *
+	 * @param int   $timestamp Timestamp of the event.
+	 * @param array $data      Data associated with the event.
+	 * @param int   $client_id ID of the client that triggered the event.
+	 */
+	public static function reader_registered( $timestamp, $data, $client_id ) {
+		$metadata = [
+			'NP_Account' => $data['user_id'],
+		];
+		if ( isset( $data['metadata']['current_page_url'] ) ) {
+			$metadata['NP_Registration Page'] = $data['metadata']['current_page_url'];
+		}
+		if ( isset( $data['metadata']['registration_method'] ) ) {
+			$metadata['NP_Registration Method'] = $data['metadata']['registration_method'];
+		}
+		self::put( $data['email'], $metadata );
+	}
+
+	/**
+	 * Handle a donation being made.
+	 *
+	 * @param int   $timestamp Timestamp of the event.
+	 * @param array $data      Data associated with the event.
+	 * @param int   $client_id ID of the client that triggered the event.
+	 */
+	public static function donation_new( $timestamp, $data, $client_id ) {
+		if ( ! isset( $data['platform_data']['order_id'] ) ) {
+			return;
+		}
+
+		$order_id = $data['platform_data']['order_id'];
+		$contact  = WooCommerce_Connection::get_contact_from_order( $order_id );
+
+		if ( ! $contact ) {
+			return;
+		}
+
+		$email    = $contact['email'];
+		$metadata = $contact['metadata'];
+		$keys     = Newspack_Newsletters::$metadata_keys;
+
+		// Only use metadata defined in 'Newspack_Newsletters'.
+		$metadata = array_intersect_key( $metadata, array_flip( $keys ) );
+
+		// Remove "product name" from metadata, we'll use
+		// 'donation_subscription_new' action for this data.
+		unset( $metadata[ $keys['product_name'] ] );
+
+		self::put( $email, $metadata );
+	}
+
+	/**
+	 * Handle a new subscription.
+	 *
+	 * @param int   $timestamp Timestamp of the event.
+	 * @param array $data      Data associated with the event.
+	 * @param int   $client_id ID of the client that triggered the event.
+	 */
+	public static function donation_subscription_new( $timestamp, $data, $client_id ) {
+		if ( empty( $data['platform_data']['order_id'] ) ) {
+			return;
+		}
+		$metadata     = [
+			'NP_Account' => $data['user_id'],
+		];
+		$order_id     = $data['platform_data']['order_id'];
+		$product_id   = Donations::get_order_donation_product_id( $order_id );
+		$product_name = get_the_title( $product_id );
+
+		$metadata['NP_Product Name'] = $product_name;
+
+		self::put( $data['email'], $metadata );
+	}
+}
+new Mailchimp();
diff --git a/includes/oauth/class-mailchimp-api.php b/includes/oauth/class-mailchimp-api.php
index e84a8c72bd..f39dea6112 100644
--- a/includes/oauth/class-mailchimp-api.php
+++ b/includes/oauth/class-mailchimp-api.php
@@ -80,18 +80,7 @@ public static function register_api_endpoints() {
 	 * @return WP_REST_Response
 	 */
 	public static function api_mailchimp_auth_status() {
-		// 'newspack_mailchimp_api_key' is a new option introduced to manage MC API key accross Newspack plugins.
-		// Keeping the old option for backwards compatibility.
-		$mailchimp_api_key = get_option( 'newspack_mailchimp_api_key', get_option( 'newspack_newsletters_mailchimp_api_key' ) );
-		$endpoint          = self::get_api_endpoint_from_key( $mailchimp_api_key );
-
-		if ( ! $mailchimp_api_key || ! $endpoint ) {
-			return \rest_ensure_response( [] );
-		}
-
-		$key_is_valid_response = self::is_valid_api_key( $endpoint, $mailchimp_api_key );
-
-		return $key_is_valid_response;
+		return self::is_valid_api_key();
 	}
 
 	/**
@@ -106,7 +95,7 @@ public static function api_mailchimp_save_key( $request ) {
 			return new \WP_Error( 'wrong_parameter', __( 'Invalid Mailchimp API Key.', 'newspack' ) );
 		}
 
-		$key_is_valid_response = self::is_valid_api_key( $endpoint, $request['api_key'] );
+		$key_is_valid_response = self::is_valid_api_key( $request['api_key'] );
 
 		if ( ! is_wp_error( $key_is_valid_response ) ) {
 			update_option( 'newspack_mailchimp_api_key', $request['api_key'] );
@@ -143,37 +132,98 @@ private static function get_api_endpoint_from_key( $api_key ) {
 	/**
 	 * Check API Key validity
 	 *
-	 * @param string $endpoint Mailchimp API Endpoint.
 	 * @param string $api_key Mailchimp API Key.
 	 * @return WP_REST_Response|WP_Error
 	 */
-	private static function is_valid_api_key( $endpoint, $api_key ) {
+	private static function is_valid_api_key( $api_key = '' ) {
 		// Mailchimp API root endpoint returns details about the Mailchimp user account.
-		$response = wp_safe_remote_get(
-			$endpoint,
-			[
-				'headers' => [
-					'Accept'        => 'application/json',
-					'Content-Type'  => 'application/json',
-					'Authorization' => "Basic $api_key",
-				],
-			]
-		);
-
+		$response = self::request( 'GET', '', [], $api_key );
 		if ( is_wp_error( $response ) ) {
 			return $response;
 		}
-		if ( 200 !== wp_remote_retrieve_response_code( $response ) ) {
-			$parsed_response = json_decode( $response['body'], true );
+		return \rest_ensure_response( [ 'username' => $response['username'] ] );
+	}
+
+	/**
+	 * Perform Mailchimp API Request
+	 *
+	 * @param string $method  HTTP method.
+	 * @param string $path    API path.
+	 * @param array  $data    Data to send.
+	 * @param string $api_key Optional API key to override the default one.
+	 *
+	 * @return array|WP_Error response body or error.
+	 */
+	public static function request( $method, $path = '', $data = [], $api_key = '' ) {
+		if ( empty( $api_key ) ) {
+			// 'newspack_mailchimp_api_key' is a new option introduced to manage MC API key accross Newspack plugins.
+			// Keeping the old option for backwards compatibility.
+			$api_key = \get_option( 'newspack_mailchimp_api_key', get_option( 'newspack_newsletters_mailchimp_api_key' ) );
+		}
+		$endpoint = self::get_api_endpoint_from_key( $api_key );
+		if ( ! $endpoint ) {
+			return new \WP_Error( 'wrong_parameter', __( 'Invalid Mailchimp API Key.', 'newspack' ) );
+		}
+		$url    = $endpoint . '/' . $path;
+		$config = [
+			'method'  => $method,
+			'headers' => [
+				'Accept'        => 'application/json',
+				'Content-Type'  => 'application/json',
+				'Authorization' => "Basic $api_key",
+			],
+		];
+		if ( ! empty( $data ) ) {
+			$config['body'] = \wp_json_encode( $data );
+		}
+		$response = \wp_safe_remote_request( $url, $config );
 
+		if ( \is_wp_error( $response ) ) {
+			return $response;
+		}
+		$parsed_response = json_decode( $response['body'], true );
+		if ( 200 !== \wp_remote_retrieve_response_code( $response ) ) {
 			return new \WP_Error(
 				'newspack_mailchimp_api',
 				array_key_exists( 'title', $parsed_response ) ? $parsed_response['title'] : __( 'Request failed.', 'newspack' )
 			);
 		}
+		return $parsed_response;
+	}
+
+	/**
+	 * Perform a GET request to Mailchimp's API
+	 *
+	 * @param string $path API path.
+	 *
+	 * @return array|WP_Error API response or error.
+	 */
+	public static function get( $path = '' ) {
+		return self::request( 'GET', $path );
+	}
 
-		$response_body = json_decode( $response['body'], true );
-		return \rest_ensure_response( [ 'username' => $response_body['username'] ] );
+	/**
+	 * Perform a PUT request to Mailchimp's API
+	 *
+	 * @param string $path API path.
+	 * @param array  $data Data to send.
+	 *
+	 * @return array|WP_Error API response or error.
+	 */
+	public static function put( $path = '', $data = [] ) {
+		return self::request( 'PUT', $path, $data );
+	}
+
+	/**
+	 * Perform a POST request to Mailchimp's API
+	 *
+	 * @param string $path API path.
+	 * @param array  $data Data to send.
+	 *
+	 * @return array|WP_Error API response or error.
+	 */
+	public static function post( $path = '', $data = [] ) {
+		return self::request( 'POST', $path, $data );
 	}
 }
 
diff --git a/includes/reader-activation/class-reader-activation.php b/includes/reader-activation/class-reader-activation.php
index efe78f0a11..d7506521fd 100644
--- a/includes/reader-activation/class-reader-activation.php
+++ b/includes/reader-activation/class-reader-activation.php
@@ -174,6 +174,7 @@ private static function get_settings_config() {
 			'sync_esp'                    => true,
 			'sync_esp_delete'             => true,
 			'active_campaign_master_list' => '',
+			'mailchimp_audience_id'       => '',
 			'emails'                      => Emails::get_emails( array_values( Reader_Activation_Emails::EMAIL_TYPES ), false ),
 			'sender_name'                 => Emails::get_from_name(),
 			'sender_email_address'        => Emails::get_from_email(),
diff --git a/includes/reader-revenue/class-woocommerce-connection.php b/includes/reader-revenue/class-woocommerce-connection.php
index 8138730088..a641c6a88e 100644
--- a/includes/reader-revenue/class-woocommerce-connection.php
+++ b/includes/reader-revenue/class-woocommerce-connection.php
@@ -163,24 +163,20 @@ public static function sync_reader_on_customer_login( $user_login, $user ) {
 	}
 
 	/**
-	 * Sync a customer to the ESP from an order.
+	 * Get the contact data from a WooCommerce order.
 	 *
-	 * @param WC_Order $order Order object.
+	 * @param \WC_Order|int $order WooCommerce order or order ID.
+	 *
+	 * @return array|false Contact data or false.
 	 */
-	public static function sync_reader_from_order( $order ) {
-		if ( ! self::can_sync_customers() ) {
-			return;
+	public static function get_contact_from_order( $order ) {
+		if ( is_integer( $order ) ) {
+			$order = new \WC_Order( $order );
 		}
-
-		if ( self::CREATED_VIA_NAME === $order->get_created_via() ) {
-			// Only sync orders not created via the Stripe integration.
-			return;
-		}
-
 		$metadata_keys = Newspack_Newsletters::$metadata_keys;
 		$user_id       = $order->get_customer_id();
 		if ( ! $user_id ) {
-			return;
+			return false;
 		}
 
 		$customer = new \WC_Customer( $user_id );
@@ -261,11 +257,33 @@ public static function sync_reader_from_order( $order ) {
 
 		$first_name = $order->get_billing_first_name();
 		$last_name  = $order->get_billing_last_name();
-		$contact    = [
+		return [
 			'email'    => $order->get_billing_email(),
 			'name'     => "$first_name $last_name",
 			'metadata' => $metadata,
 		];
+	}
+
+	/**
+	 * Sync a customer to the ESP from an order.
+	 *
+	 * @param WC_Order $order Order object.
+	 */
+	public static function sync_reader_from_order( $order ) {
+		if ( ! self::can_sync_customers() ) {
+			return;
+		}
+
+		if ( self::CREATED_VIA_NAME === $order->get_created_via() ) {
+			// Only sync orders not created via the Stripe integration.
+			return;
+		}
+
+		$contact = self::get_contact_from_order( $order );
+		if ( ! $contact ) {
+			return;
+		}
+
 		\Newspack_Newsletters_Subscription::add_contact( $contact );
 	}