Tomasz Mariusz Rząsa (Polish pronunciation: [ˈtɔmaʂ ˈʐɔ̃sa]; born 11 March 1973) is a Polish former professional footballer who primarily played as a left back and sometimes as a left midfielder who currently serves as the sporting director of Ekstraklasa club Lech Poznań.

While playing with Grasshoppers, he won two Swiss National League championships, in 1994–95 and 1995–96 seasons.

With Partizan, he was the newcomer alongside Ljubinko Drulović, Taribo West and others, where he helped the club reach the Champions League group stage.

In 2006, he came to Austria and signed with SV Ried, where he was decisive in helping them to achieve their greatest ever result – finishing as runners-up in the 2006–07 Austrian Bundesliga.

Upon finishing his playing career, he was an assistant manager at Lech Poznań under Maciej Skorża during the 2014–15 season, and under Rafał Ulatowski in May 2018.