Gene Kelly was 29 in For Me and My Gal when he played the character 'Harry Palmer'.
That was over 82 years ago in 1942.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
In 1996 he died aged 83, starring in 80 films in his career, 81 of those after For Me and My Gal was first released. If he were alive today he would be 111.
In For Me and My Gal, I think Gene Kelly looks: