Mariusz Siembida

Mariusz Siembida  (born 21 March 1975 in Puławy, Lubelskie) is a retired backstroke swimmer from Poland, who competed for his native country at two consecutive Summer Olympics, starting in 1996 (Atlanta, Georgia).

A member of Lublinianka he is best known for winning the bronze medal at the 1997 European Swimming Championships in the men's 4×100 m medley relay, alongside Marek Krawczyk, Marcin Kaczmarek and Bartosz Kizierowski.