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|