diff --git a/resources/migrations/000_migrations.yaml b/resources/migrations/000_migrations.yaml
index 71673437c898a8d82ab48ba94e4a1e77f44f2935..065beb88e9c235341fa71856e8beda2e071b8b57 100644
--- a/resources/migrations/000_migrations.yaml
+++ b/resources/migrations/000_migrations.yaml
@@ -11330,6 +11330,22 @@ databaseChangeLog:
                 AND p.object = '/general/subscription/'
               WHERE p.object IS NULL;
 
+  - changeSet:
+      id: v43.00-051
+      author: adam-james
+      comment: Added 0.43.0 - default boolean on timelines to indicate default timeline for a collection
+      changes:
+        - addColumn:
+            columns:
+            - column:
+                remarks: Boolean value indicating if the timeline is the default one for the containing Collection
+                name: default
+                type: boolean
+                defaultValue: false
+                constraints:
+                  nullable: false
+            tableName: timeline
+
 # >>>>>>>>>> DO NOT ADD NEW MIGRATIONS BELOW THIS LINE! ADD THEM ABOVE <<<<<<<<<<
 
 ########################################################################################################################
diff --git a/src/metabase/api/timeline.clj b/src/metabase/api/timeline.clj
index 3bf7e81ee24262a4f2106fe323d8db95e16816b5..00ae9b3c5ebc7903bf2ca6c186fd59f8911b3cbe 100644
--- a/src/metabase/api/timeline.clj
+++ b/src/metabase/api/timeline.clj
@@ -18,8 +18,9 @@
 
 (api/defendpoint POST "/"
   "Create a new [[Timeline]]."
-  [:as {{:keys [name description icon collection_id archived], :as body} :body}]
+  [:as {{:keys [name default description icon collection_id archived], :as body} :body}]
   {name          su/NonBlankString
+   default       (s/maybe s/Bool)
    description   (s/maybe s/Str)
    icon          (s/maybe timeline/Icons)
    collection_id (s/maybe su/IntGreaterThanZero)
@@ -73,8 +74,9 @@
 (api/defendpoint PUT "/:id"
   "Update the [[Timeline]] with `id`. Returns the timeline without events. Archiving a timeline will archive all of the
   events in that timeline."
-  [id :as {{:keys [name description icon collection_id archived] :as timeline-updates} :body}]
+  [id :as {{:keys [name default description icon collection_id archived] :as timeline-updates} :body}]
   {name          (s/maybe su/NonBlankString)
+   default       (s/maybe s/Bool)
    description   (s/maybe s/Str)
    icon          (s/maybe timeline/Icons)
    collection_id (s/maybe su/IntGreaterThanZero)
diff --git a/test/metabase/api/timeline_test.clj b/test/metabase/api/timeline_test.clj
index d7d9790e153ba075e4ac64c954ae796cd421b62b..b8165916acc723ad11dfb7882179a2be81d8db33 100644
--- a/test/metabase/api/timeline_test.clj
+++ b/test/metabase/api/timeline_test.clj
@@ -153,6 +153,7 @@
             ;; make an API call to create a timeline
             (mt/user-http-request :rasta :post 200 "timeline"
                                   {:name          "Rasta's TL"
+                                   :default       false
                                    :creator_id    (u/the-id (mt/fetch-user :rasta))
                                    :collection_id id})
             (testing "check the collection to see if the timeline is there"
diff --git a/test/metabase/test/util.clj b/test/metabase/test/util.clj
index 3a710e9870a539ed38aaa64aff18f05342ca51b3..75b6e8ce358fc5f9f62e9b6a6b4c3ec2bb30d69b 100644
--- a/test/metabase/test/util.clj
+++ b/test/metabase/test/util.clj
@@ -198,6 +198,7 @@
    Timeline
    (fn [_]
      {:name       "Timeline of bird squawks"
+      :default    false
       :creator_id (rasta-id)})
 
    TimelineEvent
@@ -242,6 +243,7 @@
                    #'Segment
                    #'Table
                    #'TaskHistory
+                   #'Timeline
                    #'User]]
   (remove-watch model-var ::reload)
   (add-watch