The closest he had to a business mentor was probably Mike Markkula who was Apple's angel investor (he also was CEO for a few years). Not strictly mentors, but

The closest he had to a business mentor was probably Mike Markkula who was Apple's angel investor (he also was CEO for a few years). Not strictly mentors, but two of his biggest influences were Paul Rand (who designed the logos for IBM and NeXT) for graphic design and Dieter Rams (who started the Functionalist School of industrial design) for product design.