Fred Leinweber competed for the US in handball (team) at the 1936 Berlin Olympics. Leinweber represented the German Sport Club in Brooklyn. He played in all three USA matches at the 1936 Olympic tournament. He was also a candidate for the American soccer delegation to the 1948 London Games, but did not make the team. Leinweber was best known as a soccer goalie, playing for the Kollsman Sport Club of the German-American Soccer League, retiring from that sport after not making the Olympic team. He married the former Lillian Hildgardner.