He was born in London, England to Welsh parents and in 1953 he moved to New Zealand with his family.
Davies won a bronze medal in the 1500 metres at the 1964 Tokyo Olympic Games, and a silver medal in the one mile event at the 1962 Commonwealth Games in Perth.
After retiring from competitive running he started coaching middle and long distance athletes, including 1976 Olympic 5000m medallist Dick Quax and 1996 Olympic 800m finalist Toni Hodgkinson.
In October 2000, Davies succeeded Sir David Beattie to become the NZOC president.