Jack Gleeson was 9 in Reign of Fire when he played the character 'Kid (uncredited)'.
That was over 22 years ago in 2002.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 31, and has starred in 6 movies in total, 4 of those since Reign of Fire was released.
In Reign of Fire, I think Jack Gleeson looks: