Bertram Leonard Wolstein (February 23, 1927 — May 17, 2004), known to his friends as Bart and publicly as Bert Wolstein, was an American real estate developer, sports team owner, and philanthropist based in Cleveland, Ohio. He founded Developers Diversified Realty Corporation (now SITE Centers), which at the time of his death was the 4th-largest developer of shopping centers in the United States. In 1979, he purchased the Cleveland Force Major Indoor Soccer League team, and attempted to purchase the Cleveland Browns in 1998. He retired from active business in 1997, and became one of the most generous donors in the United States in his final years.