Hero Fiennes Tiffin was 10 in Harry Potter and the Half-Blood Prince when he played the character 'Tom Riddle (11 Years)'.
That was over 15 years ago in 2009.
Today he is 26, and has starred in 15 movies in total, 9 of those since Harry Potter and the Half-Blood Prince was released.
In Harry Potter and the Half-Blood Prince, I think Hero Fiennes Tiffin looks: