William "Billy" Rankin (born 25 April 1959 in Lennoxtown, Scotland) is a Scottish guitarist and rock musician active in the 1980s and 1990s. Best known for his work with Nazareth (1980–83 & 1990–94), he also had a successful solo career, including a US hit single "Baby Come Back". As of 2013 Rankin is part of multi media group "Team Rock" and broadcasts "The School of Rock" show on Team Rock Radio.
Classically trained, Rankin played cello at school and was granted a Scottish Region Music Scholarship in 1971, but preferred rock music to classical as he said in an interview, 'I was probably earning more than my cello teacher and learning more than he could ever teach me just by being in a rock band.' His first band Phase played the Scottish pub circuit when he was only 15 years old and, in 1978, he joined Zal Cleminson's Zal Band, featuring members of The Sensational Alex Harvey Band.