It is, along with the DLC for it (Lost&Damned and Gay Tony)
https://www.xbox.com/en-CA/xbox-one/backward-compa...
Sorry but no. For some reason the only compatible game for Xbox one is San Andreas.
Edit: Xbox official site says that but Wikipedia says 4 is compatible so I don’t know, I’d say give it a try.
It's labeled GTA 4 on Xbox.com, not the full Grand Theft Auto 4.
It's labeled GTA 4 on Xbox.com, not the full Grand Theft Auto 4.