David "Dave" Charles Johnson (born February 20, 1947) is an American former competition swimmer and 1968 Mexico City Olympic competitor.

[2] Johnson knew little of the breaststroke or backstroke when he started swimming with the Wilmington Athletic Club and credited Mattson with his rapid success, particularly in the demanding individual medley event.

Mattson had competed and excelled in both breaststroke and the individual medley as a Collegiate swimmer at North Carolina State and used his experience to mentor Johnson.

To make an Olympic team with only five years of serious training was a rarity and a tribute to the swim program provided by Johnson's coaches Bob Mattson and later Yale's Phil Moriarty.

[4] With only two years of swimming competition behind him, on January 10, 1964, Johnson set a new Middle Atlantic American Athletic Union district and resident record of 2:07.2, easily winning the 200 Individual Medley at an Open Invitational Meet at the Suburban High pool in Wilmington.

[5] At the December 1964 Delaware State Championships at the YMCA pool in Wilmington, Johnson won both the 200-yard freestyle in a meet record time of 1:57.7, and the 200-yard Individual Medley in 2:14.0.

He had qualified for the 200 meter heats, but due to serious digestive issues from an apple he'd eaten in Mexico City that rendered him quite ill, he had to scratch.

[1] He married the former Patricia Ann Depuy and lived in Falls Church, Virginia in 1980, swimming twice a week at the George Washington University pool.

[2] He has worked as an Assistant Professor in orthopaedic surgery at George Washington University, and served as a medical consultant for the President's Council on Physical Fitness and Sports.