Sergey Viktorovich Semenov (; born 10 August 1995) is a Russian Greco-Roman wrestler who competed at the 2016 Olympic Games in the 130 kg weight category. In the semifinals he lost to Mijaín López of Cuba (0–3). In the bronze medal match he beat Heiki Nabi of Estonia (6–0). Semenov won the 2017 U23 World Championships. He is a 2017 World Cup gold medalist and a two-time silver medalist. Semenov won the 2018 World Wrestling Championships defeating American Adam Coon in the final, 9–0.