William Keller may refer to:

• William Keller (Medal of Honor) (1876–1963), U.S. Army private and Medal of Honor recipient
• William Duffy Keller (born 1934), judge
• William F. Keller (born 1951), Pennsylvania politician
• Bill Keller (born 1949), executive editor of The New York Times
• Bill Keller (televangelist), American television evangelist and the host of Live Prayer
• Billy Keller (born 1947), basketball player

• Bill Kellar (born 1956), gridiron football wide receiver