He was born Louis Jacob Weertz October 1, 1924, the son of a Lutheran minister Rev. Frederick J. Weertz) and a music teacher (Dorothea Bang Weertz), in Omaha, Nebraska, but before his first birthday the family moved to Des Moines, Iowa. He first played the piano at age three.

His first wife, Joy Dunsmoor, bore him three children. After divorcing her, he married again in 1985, to Louise DiCarlo.

In 1955 Williams recorded Autumn Leaves, the only piano instrumental to reach #1 on Billboard magazine’s popular music charts.

Until his death on October 8, 2011 from complications of pancreatic cancer, Williams resided in Encino, California and had recently bought the rights to his Kapp masters from the Universal Music Group.