Martin Smyth competed in the men’s bantamweight boxing at the 1956 Melbourne Olympic Games, one of four members of the Irish boxing team who had to overcome serious weight management challenges before and during the Games.

A member of the Star Club in Belfast, Smyth had secured Olympic selection but faced persistent difficulties making the bantamweight limit in the weeks before Melbourne. In the Games, rather than participating in the Opening Ceremony where teammate Tony Byrne carried the Irish flag, he undertook an intensive workout to make the weight limit.

He competed against the 1952 Olympic bantamweight champion Pentti Hämäläinen of Finland, with the referee stopping the contest in the second round.