John Service had the following podium finishes at major championships: 3rd in the 1954 British Empire and Commonwealth Games 3×110 yards Medley Relay (with Jack Wardrop and Bert Wardrop). Service also finished fifth in the 1954 British Empire and Commonwealth Games 220 yards breaststroke. In the British Empire and Commonwealth Games he competed for Scotland.
|1948 Summer||17||London||Swimming||Men's 200 metres Breaststroke||Great Britain||GBR||5 h1 r1/3|
|1948 Summer||17||London||Swimming||Great Britain||Round One||Heat One||5||3:00.4|