Mustafa Sayar (born April 22, 1989) is a Turkish professional cyclist riding for UCI Continental team Torku Şekerspor. In 2013, he won the sixth stage of the Tour of Turkey by powering away on the climb to Selçuk in an improbably large gear, leading to disbelief and insinuations from the live TV commentary team and other riders in the race, including Marcel Kittel, who tweeted that he was "not often in my life so angry about a result of someone else". Sayar was the first Turkish rider to provisionally win a stage in the Tour since 2008. With that result, he took the lead in the overall classification. He successfully defended the leader's jersey over the next two stages and won the race.

On July 15, 2013, he was suspended following the news that he tested positive for EPO during the Tour d'Algérie in March. As a result, he lost his overall victory in the Tour of Turkey, which went to Natnael Berhane. Sayar retired from the sport in November 2013, but returned to competition after completion of the ban.