He is best known for his role as Dr. Dick Stuart-Clark in the hugely popular British television comedy series Doctor in the House (1969-70). He is the only member of the original cast to have performed in all the sequels, Doctor at Large, Doctor in Charge, Doctor at Sea, Doctor on the Go, Doctor Down Under - filmed in Australia - and Doctor at the Top.
Back in the UK, he appeared in Bergerac and at Windsor and the Old Vic where he was in The Ghost Train. Davies also appeared in a Cinderella pantomime, where he played the role of Buttons, the servant of Cinderella's stepfather, and Cinderella's friend. He has done a number of tours of the Far East as well as Australia and New Zealand.
Davies is married to Ann. Their daughter, Emma Davies, is also an actress having appeared in film and television roles since the mid-1980s.