Leonardo Martín Mayer (locally [leoˈnarðo marˈtim maˈʝer]; German: [ˈmaɪ̯ɐ]; born May 15, 1987) is a professional tennis player from Argentina. Mayer achieved a career-high singles ranking of world no. 21 in June 2015 and world no. 58 in doubles in September 2015. He is coached by Francisco Yunis. He was born in Corrientes and resides in Buenos Aires.