Mark Dean swam for UCLA, where he earned All-American recognition. He swam in the 200 butterfly at the 1988 Seoul Olympics, missing the A Final, but winning the B Final, to place ninth overall. Dean won gold in the 200 fly at the 1991 Pan American Games. He later attended law school at St. Louis University and practiced law in St. Louis.
|1988 Summer||20||Seoul||Swimming||Men's 200 metres Butterfly||United States||USA||9|
|1988 Summer||20||Seoul||Swimming||United States||B Final||1||2:00.26||26.66||1||56.79||1||1:28.32||1||30.13 (1)||31.53 (7)||31.94 (5)|
|1988 Summer||20||Seoul||Swimming||United States||Round One||Heat Six||4||q||2:00.86||26.52||2||56.75||2||1:28.42||4||30.23 (4)||31.67 (8)||32.44 (6)|