Mateusz Kostrzewski (born 18 September 1989) is a Polish professional basketball player who last played for Wilki Morskie Szczecin of the PLK.
After many years as a successful player in Poland’s youth divisions, Kostrzewski started his professional career for the division 3 team OSSM PZKosz Sopot where he gained experience and played for Gdynia’s junior team as well. In 2008 he had his first games for Gdynia’s senior team and played his first Euroleague game in 2010. Between 2008 and 2010, he gained further experience at Gdynia’s 2nd and 3rd team as well as its youth teams.
In the 2018–19 season, he won the Polish Basketball Cup with Stal Ostrów Wielkopolski and was named the tournament's Most Valuable Player. The following season, he averaged 13.1 points and 5.6 rebounds per game. On 6 June 2020 he extended his contract for an additional season.
On 26 July 2021 he signed with Start Lublin of the PLK.