How to stop Gradle task execution in Android Studio?

No, Gradle (as of this writing, v1.10) has a limitation that you can't cancel tasks through its tooling API, which is what Android Studio uses to communicate with its daemon. You can track the progress of this at https://code.google.com/p/android/issues/detail?id=59464 . It's also preventing progress on something else we'd like to be able to do, https://code.google.com/p/android/issues/detail?id=59965

In the meantime about all you can do is to go through your OS and kill the Gradle processes manually, which is a little painful and messy. It's possible that it could leave your build in some intermediate bad state which would mess up future incremental compiles, but I don't know for sure.

you can call ./gradlew --stop in a Terminal and it will kill all gradle processes