Noah Wyle was 12 in Lust in the Dust when he played the character 'Young Man (uncredited)'.
That was over 39 years ago in 1984.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 52, and has starred in 30 movies in total, 28 of those since Lust in the Dust was released.
In Lust in the Dust, I think Noah Wyle looks: