Ali Eren Demirezen (born April 2, 1990 in Samsun, Turkey) is a Turkish amateur boxer competing in the super heavyweight (+91 kg) division. The 1.90 m (6 ft 3 in) athlete is a member of Fenerbahçe Boxing in Istanbul.
Demirezen won the silver medal at the 2013 Mediterranean Games in Mersin, Turkey.
At the 2013 AIBA World Boxing Championships in Almaty, Kazakhstan, he was eliminated already in the first round.
In 2015, he competed at the European Amateur Boxing Championships in Samokov, Bulgaria. He was eliminated in the quarterfinals, however, was qualified to participate at the AIBA World Boxing Championships the same year. He was defeated by Joe Joyce from England in the Section 2 quarterfinals of the 2015 AIBA World Boxing Championships in Doha, Qatar.
He earned a quota spot for 2016 Summer Olympics after taking a bronze medal at the 2016 European Boxing Olympic Qualification Tournament in Samsun, Turkey.