Weiser was born in Chicago, Illinois, to David and Audra Weiser. Weiser grew up in Stony Brook, New York. He moved to Sarasota, Florida, to study philosophy at New College of Florida but dropped out in his second year when he ran out of money. He then moved to Ann Arbor, Michigan, where he found a job as a computer programmer. While working as a computer programmer he began taking computer science classes and excelled to the point that he was directly admitted into a master's program at the University of Michigan. He studied Computer and Communication Science at the University of Michigan, receiving an M.A. in 1976 and a Ph.D. in 1979. Weiser later taught computer science at the University of Maryland, College Park and became associate chairman of the department in 1986.