Mateusz Polaczyk (born 22 January 1988) is a Polish slalom canoeist who has competed at the international level since 2004.

Polaczyk finished 4th in the K1 event at the 2012 Summer Olympics in London.

[1] He won seven medals at the ICF Canoe Slalom World Championships with four silvers (K1: 2011, 2015; K1 team: 2013, 2018) and three bronzes (K1: 2013, K1 team: 2006, 2023).

He also won three golds, three silvers and three bronzes at the European Championships, including a silver in the K1 team event at the 2023 European Games in Kraków.

[2] He has four brothers (Grzegorz, Rafał, Henryk and Łukasz) and two sisters (Joanna Mędoń and Iwona) all of whom have competed in canoe slalom.