William Adelbert Foster
- Category : 1915-births
- Type : R
- Profile : 4/6 - Opportunistic / Role Model
- Definition : None
- Incarnation Cross : RAX Contagion 1
American military, United States Marine who received the Medal of Honor for his "conspicuous gallantry and intrepidity at the risk of his life above and beyond the call of duty" during World War II during the Battle of Okinawa in 1945. He died on 2 May 1945.