David Harmon competed in the men’s freestyle wrestling at the 1988 Seoul Olympic Games in his first year as a senior wrestler, losing both his bouts and being eliminated.

Prior to the Games, Harmon trained with the USA wrestling squad at Oklahoma University on a full-time basis for a number of months. In Seoul, Harmon suffered an ankle injury in training which then flared up again in the warm up, resulting in him competing with the injury.

As of 2026, Harmon is the most recent Irish wrestling athlete to compete at the Olympic Games.