Mariusz Witecki (born 10 May 1981) is a Polish former professional road bicycle racer, who rode professionally between 2003 and 2016 for the Team Volksbank, Mróz–Active Jet, CCC–Polsat–Polkowice, Bank BGŻ and Domin Sport teams. He now works as a directeur sportif for UCI Continental team Voster ATS Team.

Born in Kielce, Witecki won the five-day Course de la Solidarité Olympique stage race in Poland in July 2012, beating Team NetApp's Bartosz Huzarski by five seconds.