Alexander Murray Hannum (July 19, 1923 – January 18, 2002) was an American professional basketball player and coach. Known as Sarge because of his military background, Hannum played center for six different teams, most notably the Milwaukee (later St. Louis) Hawks in the National Basketball Association (NBA), where he spent three seasons.

Hannun went on to coach for 12 seasons in the NBA, where his Hawks captured the 1958 league championship and his Philadelphia 76ers did likewise nine years later. In that span, Hannum became known as something of a Boston Celtics killer, as his were the only teams to interrupt their 13-year dynasty.

After Hannum moved on to the rival American Basketball Association (ABA), he guided the Oakland Oaks to the 1968-69 championship to become the first coach to win NBA and ABA titles. Bill Sharman was the only other coach to achieve the feat.

Hannum was inducted into the Naismith Memorial Basketball Hall of Fame in 1998.

Alexander Murray Hannum was born on July 19, 1923, in Los Angeles, California. He attended Hamilton High School, where he excelled in basketball.

Hannum attended the University of Southern California (USC). He played basketball at USC in 1942 and 1943, but his time at USC was interrupted when he was called into military service during World War II in 1943. After three years in the military, he returned to USC for the 1946–47 and 1947–48 school years. During his senior year, he was captain of the 1948 team, and was an All-Conference selection.

He played basketball at USC under Naismith Memorial Basketball Hall of Fame coach Sam Barry. In addition to Hannum, Barry coached two other future Hall of Fame coaches in college, Tex Winter and Bill Sharman. Sharman was Hannum's teammate from 1946 to 1948 at USC. Both played with Winter at USC during the 1946-47 season.

On May 10, 1948, Hannum was drafted by the Indianapolis Jets in the 4th round of the 1948 BAA Draft.