John Michael Piersma (born January 25, 1975) is an American former competition swimmer who represented the United States at the 1996 Summer Olympics in Atlanta. Piersma competed in the B Finals of the men's 200-meter freestyle and men's 400-meter freestyle. In the 200-meter freestyle, he finished twelfth overall with a time 1:49.90; he placed ninth overall in the 400-meter freestyle with a time of 3:50.69.[1]