Walt Disney was 19 in Newman Laugh-O-Grams when he played the character 'Himself'.
That was over 102 years ago in 1921.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
In 1966 he died aged 65, starring in 217 films in his career, 216 of those after Newman Laugh-O-Grams was first released. If he were alive today he would be 122.
In Newman Laugh-O-Grams, I think Walt Disney looks: