William Curry Keller (born August 30, 1947) is an American retired professional basketball player.

Keller attended Purdue University, located in West Lafayette, Indiana, where he played under head coach George King.

He received the Frances Pomeroy Naismith Award his senior year, which is given to the nation's best player under 6 feet (1.8 m).

After his Senior season at Purdue, he participated in the Kentucky-Indiana College All-Star Game, where he first played with a three-point line.

Billy was the 2nd pick in the 7th round of the 1969 NBA draft to the Milwaukee Bucks, but only played for the ABA's Indiana Pacers.