diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a83da0adf6..1a9e8aede0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -231,7 +231,14 @@ jobs:
         - backend: "iOS"
           platform: "iOS"
           runs-on: "macos-14"
-          briefcase-run-args: "--device 'iPhone SE (3rd generation)'"
+          # As of early April 2024, the XCode 15/iOS 17 simulator had a performance
+          # issue that rendered Github Actions testing impossible. The issue didn't
+          # impact iOS 16.4, but that required the use of Xcode 14.3.1.
+          #
+          # Refs #2476, actions/runner-images#9591.
+          pre-command: "sudo xcode-select -s /Applications/Xcode_14.3.1.app"
+          briefcase-run-args: "--device 'iPhone SE (3rd generation)::iOS 16.4'"
+          # briefcase-run-args: "--device 'iPhone SE (3rd generation)'"
           app-user-data-path: "$(xcrun simctl get_app_container booted org.beeware.toga.testbed data)/Documents"
 
         - backend: "android"
diff --git a/changes/2476.misc.rst b/changes/2476.misc.rst
new file mode 100644
index 0000000000..864e366381
--- /dev/null
+++ b/changes/2476.misc.rst
@@ -0,0 +1 @@
+iOS CI testing was reverted to use XCode 14.3.1 and iOS 16.4, due to a performance issue with Github Actions.