Sergey Nikolayev (Russian: Сергей Николаев; born 12 November 1966) is a Russian former track and field athlete who competed in the shot put. He set a personal best of 21.35 m (70 ft 0 1⁄2 in) in 1989. He represented the Soviet Union at the 1991 World Championships in Athletics, placing fifth, and was a two-time participant at the at European Athletics Championships (1990, 1994). His highest world seasonal ranking – sixth – came in 1989.
Nikolayev was a silver medallist at the 1992 IAAF World Cup. He was also bronze medallist on home turf at the 1994 Goodwill Games, taking third behind Americans C. J. Hunter and Randy Barnes.
He was twice national champion at the Russian Athletics Championships, winning the shot put in 1994 and 1998. He competed as a guest at the Japan Championships in Athletics in 1990 and won in a meet record of 19.02 m (62 ft 4 3⁄4 in).