John Joseph Macionis (/məˈʃoʊnɪs/ mə-SHOH-nis; May 27, 1916 – February 16, 2012)[1] was an American competition swimmer who represented the United States at the 1936 Summer Olympics in Berlin.

Born in Philadelphia, Macionis swam for Big Brothers, Germantown Y.M.C.A., and Central High School, where he captained the swim team and set a world's record in the 200-yard freestyle in 1933.

[2] Macionis said he was the son of working class Lithuanian immigrants, who, in the midst of the Great Depression, could not afford the cost of tuition at the private boarding school.

Eventually, because Edwards was so impressed with Macionis, the fee was reduced, and Mercersburg gained one of the greatest athletes in its history.

The transition from Philadelphia's Central High School to Mercersburg was not easy: "I had to take all the College Board subjects and I flunked them all.

A Harvard University newspaper provides some results from a Yale-Harvard dual meet held in the Yale pool in March 1936.

[6] A Yale University "Banner Yearbook and Pot Pourri entry for the Class of 1937 (page 224), records the 1936 indoor season for the Bulldog swim team: "On the 13th of February (1936) the Naval Academy was host to the team at Annapolis, and the next day Yale broke pool records and an Intercollegiate mark in the 50-yard pool, (including) Macionis swimming the 440 in 5 minutes 8 and nine-tenths seconds."

[7] At the 1935 AAU outdoor national championships, held in New York City's 50-meter Manhattan Beach pool in July of that year, he won the 440-yard Freestyle, beating competitors including Jack Medica, Ralph Flanagan, and James Gilhula, all of whom were world record holders at varying freestyle distances.

He served as a commissioned officer in the United States Coast Guard during World War II, attaining the rank of lieutenant commander.