Marcin Polak (born 25 November 1982) is a Polish para-cyclist. He represented Poland at the 2016 and 2020 Summer Paralympics.
On 31 January 2020, Polak set the world record in the 4 km individual pursuit in the B classification with a time of 4 minutes 3.528 seconds.
He won a bronze medal in the men's individual pursuit B event at the 2020 Summer Paralympics. On 31 May 2022, he was stripped of his medal and suspended for four years for breaching anti-doping rules.