In 1965, he was awarded two scholarships to attend the Parsons School of Design in New York. He graduated from high school in 1967 and began working full-time. By 1969, his name could be found on the label of apparel produced by Digits, a sportswear manufacturer. Smith subsequently established his own clothing company and fashion brand, Williwear.

Smith’s apparel company, “Williwear Ltd.,” sold $25 million worth of clothing per year at the height of his success in the industry. The wedding gown worn by Mary Jane Watson when she married Spider-Man in the Spider-Man comic book and comic strip in 1987, as well as the homecoming gowns in Spike Lee’s School Daze, were designed by him. Smith passed away in 1987 after suffering shigella and pneumonia while on vacation to India, according to his family. At the time of his passing, Willi Smith was one of the most successful Black designers in the fashion industry.