Mariusz Witecki (born 10 May 1981) is a Polish professional road bicycle racer who rides for UCI Continental Team Bank BGŻ.

Born in Kielce, Witecki has competed as a professional since 2003 – with the exception of 2008 – mainly competing for domestic Polish teams such as CCC–Polsat–Polkowice and Bank BGŻ, who he joined in 2012. In July 2012, Witecki won the five-day Course de la Solidarité Olympique stage race in Poland, beating Team NetApp's Bartosz Huzarski by five seconds.