diff --git a/packages/url_launcher/url_launcher_ios/CHANGELOG.md b/packages/url_launcher/url_launcher_ios/CHANGELOG.md
index 0c6d13e0941e..63dbcaa6a48d 100644
--- a/packages/url_launcher/url_launcher_ios/CHANGELOG.md
+++ b/packages/url_launcher/url_launcher_ios/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 6.3.1
+
+* Fixes a compile error when comforming UIApplication to Launcher in iOS 18 Beta 3.
+
 ## 6.3.0
 
 * Adds Swift Package Manager compatibility.
diff --git a/packages/url_launcher/url_launcher_ios/ios/url_launcher_ios/Sources/url_launcher_ios/Launcher.swift b/packages/url_launcher/url_launcher_ios/ios/url_launcher_ios/Sources/url_launcher_ios/Launcher.swift
index 454dd53fbb9c..1f64b95c642d 100644
--- a/packages/url_launcher/url_launcher_ios/ios/url_launcher_ios/Sources/url_launcher_ios/Launcher.swift
+++ b/packages/url_launcher/url_launcher_ios/ios/url_launcher_ios/Sources/url_launcher_ios/Launcher.swift
@@ -18,5 +18,21 @@ protocol Launcher {
     completionHandler completion: ((Bool) -> Void)?)
 }
 
-/// Launcher is intentionally a direct passthroguh to UIApplication.
-extension UIApplication: Launcher {}
+// TODO(hellohuanlin): This wrapper is a workaround for iOS 18 Beta 3 where completionHandler is annotated with @MainActor @Sendable, resulting in compile error when conforming UIApplication to Launcher. We should try again in newer betas.
+/// A default URL launcher.
+final class DefaultLauncher: Launcher {
+  func canOpenURL(_ url: URL) -> Bool {
+    return UIApplication.shared.canOpenURL(url)
+  }
+
+  func open(
+    _ url: URL,
+    options: [UIApplication.OpenExternalURLOptionsKey: Any],
+    completionHandler completion: ((Bool) -> Void)?
+  ) {
+    UIApplication.shared.open(
+      url,
+      options: options,
+      completionHandler: completion)
+  }
+}
diff --git a/packages/url_launcher/url_launcher_ios/ios/url_launcher_ios/Sources/url_launcher_ios/URLLauncherPlugin.swift b/packages/url_launcher/url_launcher_ios/ios/url_launcher_ios/Sources/url_launcher_ios/URLLauncherPlugin.swift
index 44718dee7323..9fdec7ee5ae3 100644
--- a/packages/url_launcher/url_launcher_ios/ios/url_launcher_ios/Sources/url_launcher_ios/URLLauncherPlugin.swift
+++ b/packages/url_launcher/url_launcher_ios/ios/url_launcher_ios/Sources/url_launcher_ios/URLLauncherPlugin.swift
@@ -22,7 +22,7 @@ public final class URLLauncherPlugin: NSObject, FlutterPlugin, UrlLauncherApi {
     UIApplication.shared.keyWindow?.rootViewController?.topViewController
   }
 
-  init(launcher: Launcher = UIApplication.shared) {
+  init(launcher: Launcher = DefaultLauncher()) {
     self.launcher = launcher
   }
 
diff --git a/packages/url_launcher/url_launcher_ios/pubspec.yaml b/packages/url_launcher/url_launcher_ios/pubspec.yaml
index 65e9c2048351..25a227503f0e 100644
--- a/packages/url_launcher/url_launcher_ios/pubspec.yaml
+++ b/packages/url_launcher/url_launcher_ios/pubspec.yaml
@@ -2,7 +2,7 @@ name: url_launcher_ios
 description: iOS implementation of the url_launcher plugin.
 repository: https://github.com/flutter/packages/tree/main/packages/url_launcher/url_launcher_ios
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+url_launcher%22
-version: 6.3.0
+version: 6.3.1
 
 environment:
   sdk: ^3.2.3