Michal Mertiňák (born 11 October 1979) is a retired professional tennis player from Slovakia.

He turned professional in 1999, and has won six doubles titles in his career on the ATP Tour.

He reached his career high doubles ranking of World No.

He played in the 2005 Davis Cup for Slovakia, who finished runner-up to Croatia.

Mertiňák played two ties in the final, including losing the deciding fifth rubber to Mario Ančić.