Who was the youngest driver ever to retire from F1?

May be...

Tuero

I think Mike Thackwell was the youngest to retire from a race, but career wise as others have said, Ebastien Tuero.

You're looking for a driver who actually retired.

(The youngest driver ever to have a "last" GP was Ricardo Rodriguez, but his career was cut short by his death, not his retirement.)

Montoya or Yoong. One is doing Nascar and the other one is doing whatever he can to stay in motorsport trying out speedcar and a1gp so i guess they aren't really retired from racing but they are retired from F1, sort of.

Hmm... Scott Speed comes to mind but did he actually retire?