Sergei Sergeyevich Plotnikov (Russian: Сергей Сергеевич Плотников; born 3 June 1990) is a Russian professional ice hockey forward who currently plays for SKA Saint Petersburg of the Kontinental Hockey League (KHL). Plotnikov previously played in the KHL with Amur Khabarovsk and Lokomotiv Yaroslavl. He has played briefly in the National Hockey League with the Pittsburgh Penguins and the Arizona Coyotes.
Plotnikov was not drafted by any NHL team. On 1 July 2015, Plotnikov bought out the final year of his contract with Lokomotiv Yaroslavl. He signed a one-year, entry-level contract with the NHL's Pittsburgh Penguins.
In his first North American season in 2015–16, Plotnikov scored just two points in 32 games. From December 2015 on, he was a healthy scratch for almost two months. Displeased with his lack of playing time, Plotnikov requested a trade and was subsequently traded to the Arizona Coyotes on 29 February 2016, in exchange for Matthias Plachta and a conditional seventh round draft pick in 2016, dependent on if the Coyotes resigned him. Plotnikov's struggles continued with the Coyotes, unable to find his offensive touch with 1 assist from 13 games.