Over time I collected several Android emulators, many of which I no longer used.

Deleting the emulator itself was straightforward enough, but deleting the underlying system image was a bit more hidden.

Deleting an emulator

1. In Android Studio, open the AVD Manager from “Tools” → “AVD Manager”, where you’d normally launch an emulator.

2. In the “Actions” column, click the arrow pointing down to open the menu for the emulator you want to delete.

3. Select “Delete” and confirm in the dialog.

Deleting a system image

1. In Android Studio, open the SDK Manager from “Tools” → “SDK Manager”.

2. Ensure you’re on the “SDK Platform” tab (default)

3. Below the list, tick the checkbox “Show Package Details”

4. If you have some very old system images, untick “Hide Obsolete Packages”

5. Find all the ticked “System Image” entries in the list that you no longer want, and untick them

6. Click “Apply” (or “OK”), then “OK” in the dialog that comes up. The dialog helpfully tells you how much disk space you’ll be saving.