Jeff Conaway (born October 5, 1950, New York, New York) is an American actor best known for his roles as Kenickie in the 1978 musical Grease (and the replacement Danny Zuko in the original Broadway production-he played the dance show host in a recent Broadway revival), and as Bobby Wheeler on the 1980s television series Taxi. He also starred on the short lived 1980s tv series Wizards and Warriors, and as Security Chief Zack Allen on the 1990s science-fiction series Babylon 5.
He began acting on Broadway at the age of ten. He made an appearance in the film Jawbreaker as the father of one of the teenage girls. He has made guest appearances on shows ranging from Barnaby Jones to George and Leo.
Problems with drugs contributed to his divorce from Rona Newton-John, sister of Olivia Newton-John. He was on Celebrity Fit Club 3 for a few weeks until entering a rehab clinic.