Oliver Marach (born 16 July 1980) is a former Austrian professional tennis player who primarily specialised in doubles.

Marach won his first Grand Slam title at the 2018 Australian Open, partnering Mate Pavić,[1] and the pair also finished runners-up at the 2017 Wimbledon Championships and 2018 French Open.

In mixed doubles, he has reached three Grand Slam semifinals.

He has represented Austria in the Davis Cup since 2003, and also played at the 2016 Olympic Games alongside Alexander Peya.

[2] Marach retired from professional tennis in December 2022.