My first choice would be a doctor or surgeon of some sort. Preferably one with wide knowledge of herbal medicine aswell. There’s a plenty of problems I’m going to face in the post apocalyptic world but for the most part it’s things I can either figure out myself or live without, but medicine is not one of those things.

If it absolutely has to be a famous person then I’d say Jordan Jonas whose the winner of the 6th season of “Alone”

Leonardo da Vinci.

Not only he was a brilliant artist but also a highly skilled inventor, engineer, and scientist. His diverse range of skills and knowledge would make him an invaluable asset in a survival situation. His skills will be quite outdated, yes, but it is perfectly fixable.