Billy Kerr first competed internationally in 1978 when he represented Northern Ireland at the Commonwealth Games in the road race and team pursuit. He again represented Ulster at the 1982 Commonwealth Games, helping them to a fourth-place in the team time trial. Kerr competed three times for Ireland at the World Championships in the team time trial, in 1978-79 and 1982, with a best finish for the team of 19th in 1979. Kerr’s two greatest victories came in 1981 and 1982 when he won the Tour of Ireland both years. He also won the Tour of the North in 1978 and 1979, as well as the Sealink International Stage Race in England.