Martin Joseph Damm Jr. (born 30 September 2003) is an American professional tennis player. On the junior tour, Damm has a career high junior ranking of 3, achieved on 1 January 2021. In August 2019, Damm and his partner Toby Kodat won the USTA Boys 18s National Championships doubles title, earning the pair a wild-card entry into the doubles main draw of the 2019 US Open. Damm and fellow American Toby Kodat became the youngest men's doubles team to win a US Open match in the Open Era. Damm is the son of former tennis player Martin Damm.