Ján Krošlák (born 17 October 1974 in Bratislava) is a former tennis player from Slovakia, who turned professional in 1993.
He represented his native country at the 1996 Summer Olympics in Atlanta, United States, where he was defeated in the first round by America's MaliVai Washington.[1] The right-hander reached his highest singles ATP-ranking on 13 September 1999, when he became the number 53 of the world.
In the 1998 Davis Cup he played with Martin Hromec.