William Mark Tosheff (June 2, 1926 – October 1, 2011) was an American professional basketball player.

A 6'1" guard, Tosheff played at Indiana University from 1947 to 1951 after a stint with the U.S. Army Air Corps.

[1] From 1951 to 1954, he played in the NBA as a member of the Indianapolis Olympians and Milwaukee Hawks, averaging 9.2 points in 203 games.

[4] Tosheff lobbied to close a loophole in the NBA pension that granted benefits to post-1965 players with a minimum of three years of service, but required pre-1965 players have five years of service.

[5] A San Diego resident, Tosheff died in Hawaii from cancer aged 85 on October 1, 2011.