diff --git a/modules/checkout/commerce_checkout.services.yml b/modules/checkout/commerce_checkout.services.yml
index 29b44dde..a8268254 100644
--- a/modules/checkout/commerce_checkout.services.yml
+++ b/modules/checkout/commerce_checkout.services.yml
@@ -12,7 +12,7 @@ services:
 
   commerce_checkout.checkout_order_manager:
     class: Drupal\commerce_checkout\CheckoutOrderManager
-    arguments: ['@commerce_checkout.chain_checkout_flow_resolver']
+    arguments: ['@commerce_checkout.chain_checkout_flow_resolver', '@event_dispatcher']
 
   plugin.manager.commerce_checkout_flow:
     class: Drupal\commerce_checkout\CheckoutFlowManager
diff --git a/modules/checkout/src/CheckoutOrderManager.php b/modules/checkout/src/CheckoutOrderManager.php
index f396d514..a7763537 100644
--- a/modules/checkout/src/CheckoutOrderManager.php
+++ b/modules/checkout/src/CheckoutOrderManager.php
@@ -2,8 +2,11 @@
 
 namespace Drupal\commerce_checkout;
 
+use Drupal\commerce_checkout\Event\CheckoutEvents;
 use Drupal\commerce_checkout\Resolver\ChainCheckoutFlowResolverInterface;
 use Drupal\commerce_order\Entity\OrderInterface;
+use Drupal\commerce_order\Event\OrderEvent;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 
 /**
  * Manages checkout flows for orders.
@@ -17,14 +20,24 @@ class CheckoutOrderManager implements CheckoutOrderManagerInterface {
    */
   protected $chainCheckoutFlowResolver;
 
+  /**
+   * The event dispatcher.
+   *
+   * @var \Symfony\Component\EventDispatcher\EventDispatcherInterface
+   */
+  protected $eventDispatcher;
+
   /**
    * Constructs a new CheckoutOrderManager object.
    *
    * @param \Drupal\commerce_checkout\Resolver\ChainCheckoutFlowResolverInterface $chain_checkout_flow_resolver
    *   The chain checkout flow resolver.
+   * @param \Symfony\Component\EventDispatcher\EventDispatcherInterface $event_dispatcher
+   *   The event dispatcher.
    */
-  public function __construct(ChainCheckoutFlowResolverInterface $chain_checkout_flow_resolver) {
+  public function __construct(ChainCheckoutFlowResolverInterface $chain_checkout_flow_resolver, EventDispatcherInterface $event_dispatcher) {
     $this->chainCheckoutFlowResolver = $chain_checkout_flow_resolver;
+    $this->eventDispatcher = $event_dispatcher;
   }
 
   /**
@@ -32,9 +45,7 @@ class CheckoutOrderManager implements CheckoutOrderManagerInterface {
    */
   public function getCheckoutFlow(OrderInterface $order) {
     if (!$order->get('checkout_flow')->entity) {
-      $checkout_flow = $this->chainCheckoutFlowResolver->resolve($order);
-      $order->set('checkout_flow', $checkout_flow);
-      $order->save();
+      $this->resolveCheckoutFlow($order);
     }
 
     return $order->get('checkout_flow')->entity;
@@ -68,4 +79,40 @@ class CheckoutOrderManager implements CheckoutOrderManagerInterface {
     return $selected_step_id;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function isInitialized(OrderInterface $order) {
+    // Note that we don't check whether the "checkout_init_event_dispatched"
+    // flag is set here on purpose to make sure we don't fire the event for
+    // existing orders that potentially already entered checkout.
+    return !$order->get('checkout_flow')->isEmpty() && $order->get('checkout_flow')->entity;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function initialize(OrderInterface $order) {
+    if (!$order->getData('checkout_init_event_dispatched', FALSE)) {
+      $event = new OrderEvent($order);
+      $this->eventDispatcher->dispatch(CheckoutEvents::INIT, $event);
+      $order->setData('checkout_init_event_dispatched', TRUE);
+    }
+    $this->resolveCheckoutFlow($order);
+  }
+
+  /**
+   * Resolves the checkout flow for the given order.
+   *
+   * @param \Drupal\commerce_order\Entity\OrderInterface $order
+   *   The order.
+   *
+   * @throws \Drupal\Core\Entity\EntityStorageException
+   */
+  protected function resolveCheckoutFlow(OrderInterface $order) {
+    $checkout_flow = $this->chainCheckoutFlowResolver->resolve($order);
+    $order->set('checkout_flow', $checkout_flow);
+    $order->save();
+  }
+
 }
diff --git a/modules/checkout/src/CheckoutOrderManagerInterface.php b/modules/checkout/src/CheckoutOrderManagerInterface.php
index fed44246..8c6a600e 100644
--- a/modules/checkout/src/CheckoutOrderManagerInterface.php
+++ b/modules/checkout/src/CheckoutOrderManagerInterface.php
@@ -16,7 +16,7 @@ interface CheckoutOrderManagerInterface {
    *   The order.
    *
    * @return \Drupal\commerce_checkout\Entity\CheckoutFlowInterface
-   *   THe checkout flow.
+   *   The checkout flow.
    */
   public function getCheckoutFlow(OrderInterface $order);
 
@@ -37,4 +37,26 @@ interface CheckoutOrderManagerInterface {
    */
   public function getCheckoutStepId(OrderInterface $order, $requested_step_id = NULL);
 
+  /**
+   * Determines whether the given order is initialized for checkout.
+   *
+   * @param \Drupal\commerce_order\Entity\OrderInterface $order
+   *   The order.
+   *
+   * @return bool
+   *   Returns whether the order is initialized for checkout.
+   */
+  public function isInitialized(OrderInterface $order);
+
+  /**
+   * Initializes the order for checkout
+   *
+   * This sets the order's checkout flow and dispatches the checkout init event
+   * for other modules to act on the order.
+   *
+   * @param \Drupal\commerce_order\Entity\OrderInterface $order
+   *   The order.
+   */
+  public function initialize(OrderInterface $order);
+
 }
diff --git a/modules/checkout/src/Controller/CheckoutController.php b/modules/checkout/src/Controller/CheckoutController.php
index 87aa7019..6bf4f2a6 100644
--- a/modules/checkout/src/Controller/CheckoutController.php
+++ b/modules/checkout/src/Controller/CheckoutController.php
@@ -82,6 +82,11 @@ class CheckoutController implements ContainerInjectionInterface {
   public function formPage(RouteMatchInterface $route_match) {
     /** @var \Drupal\commerce_order\Entity\OrderInterface $order */
     $order = $route_match->getParameter('commerce_order');
+
+    if (!$this->checkoutOrderManager->isInitialized($order)) {
+      $this->checkoutOrderManager->initialize($order);
+    }
+
     $requested_step_id = $route_match->getParameter('step');
     $step_id = $this->checkoutOrderManager->getCheckoutStepId($order, $requested_step_id);
     if ($requested_step_id != $step_id) {
diff --git a/modules/checkout/src/Event/CheckoutEvents.php b/modules/checkout/src/Event/CheckoutEvents.php
index 5a01f479..1859a7c6 100644
--- a/modules/checkout/src/Event/CheckoutEvents.php
+++ b/modules/checkout/src/Event/CheckoutEvents.php
@@ -16,4 +16,13 @@ final class CheckoutEvents {
    */
   const COMPLETION_REGISTER = 'commerce_checkout.completion_register';
 
+  /**
+   * Name of the event fired when the customer enters checkout the first time.
+   *
+   * @Event
+   *
+   * @see \Drupal\commerce_checkout\Event\CheckoutInitEvent
+   */
+  const INIT = 'commerce_checkout.init';
+
 }
diff --git a/modules/checkout/tests/src/Kernel/CheckoutOrderManagerTest.php b/modules/checkout/tests/src/Kernel/CheckoutOrderManagerTest.php
index aaa4e5b6..eae86873 100644
--- a/modules/checkout/tests/src/Kernel/CheckoutOrderManagerTest.php
+++ b/modules/checkout/tests/src/Kernel/CheckoutOrderManagerTest.php
@@ -74,6 +74,20 @@ class CheckoutOrderManagerTest extends OrderKernelTestBase {
     $this->container->get('request_stack')->push($request);
   }
 
+  /**
+   * Tests initializing the order for checkout.
+   */
+  public function testInitialize() {
+    $this->assertFalse($this->checkoutOrderManager->isInitialized($this->order));
+
+    $this->checkoutOrderManager->initialize($this->order);
+    $checkout_flow = $this->checkoutOrderManager->getCheckoutFlow($this->order);
+    $this->assertInstanceOf(CheckoutFlow::class, $checkout_flow);
+    $this->assertEquals('default', $checkout_flow->id());
+    $this->assertTrue($this->order->getData('checkout_init_event_dispatched'));
+    $this->assertTrue($this->checkoutOrderManager->isInitialized($this->order));
+  }
+
   /**
    * Tests getting the order's checkout flow.
    */