Allen Gilchrist had the following podium finishes at major championships: 2nd in the 1950 British Empire Games 3×110 yards Medley Relay (with Lucien Beaumont and Peter Salmon), 2nd in the 1954 British Empire and Commonwealth Games 4×220 yards Freestyle Relay (with George Park, Gerry McNamee, and the non-Olympian Ted Simpson); 3rd in the 1955 Pan American Games 4×200 metre Freestyle Relay (with George Park, Gerry McNamee, and the non-Olympian Ted Simpson).
Gilchrist also finished fourth in the 1950 British Empire Games 4×220 yards freestyle relay (with Leo Portelance, Peter Salmon, and the non-Olympian Jim Portelance), but was eliminated in the heats of the 1950 British Empire Games 440 yards freestyle. Four years later at the 1954 British Empire and Commonwealth Games he was again eliminated in the heats of the 440 yards freestyle.
|1948 Summer||16||London||Swimming||Men's 400 metres Freestyle||Canada||CAN||6 h3 r1/3|
|1948 Summer||16||London||Swimming||Men's 1,500 metres Freestyle||Canada||CAN||7 h4 r1/3|
|1948 Summer||16||London||Swimming||Men's 4 × 200 metres Freestyle Relay||Canada||CAN||6 h2 r1/2|
|1952 Summer||20||Helsinki||Swimming||Men's 400 metres Freestyle||Canada||CAN||5 h3 r2/3|
|1952 Summer||20||Helsinki||Swimming||Men's 1,500 metres Freestyle||Canada||CAN||4 h5 r1/2|
|1952 Summer||20||Helsinki||Swimming||Men's 4 × 200 metres Freestyle Relay||Canada||CAN||4 h3 r1/2|
|1948 Summer||16||London||Swimming||Canada||Round One||Heat Three||6||5:21.5|
|1952 Summer||20||Helsinki||Swimming||Canada||Semi-Finals||Heat Three||5||4:52.4|
|1952 Summer||20||Helsinki||Swimming||Canada||Round One||Heat Three||3||QU||4:52.5|
|1948 Summer||16||London||Swimming||Canada||Round One||Heat Four||7||23:00.6|
|1952 Summer||20||Helsinki||Swimming||Canada||Round One||Heat Five||4||20:08.3|