Is it possible to mass delete Bluetooth devices on my iPhone?

No, you'll have to delete them one by one. I'm sure this is quite purposeful. Imagine how upset people might get if they accidentally removed all Bluetooth pairings from their phone, then had to go through and re-pair devices.

iRusland wrote:

Sure, but imagine deleting photos one by one, because how upset people might get if they accidentally removed all photos from their phone.

I currently have 209 Bluetooth devices in settings. And to forget them I need to make 209*3 == 627 actions manually! I want to have an option to “Select” the ones I don’t need and delete them.

Sorry, this is how it works, so there's nothing anyone here on this user to user only forum can do to change how to remove BT devices.

Feel free to make a feature request to Apple here --> Feedback - iPhone - Apple

Sure, but imagine deleting photos one by one, because how upset people might get if they accidentally removed all photos from their phone.

I currently have 209 Bluetooth devices in settings. And to forget them I need to make 209*3 == 627 actions manually! I want to have an option to “Select” the ones I don’t need and delete them.