Sergei Konstantinovich Popov (Russian: Сергей Константинович Попов, 21 September 1930 – 25 June 1995) was a Russian marathon runner.

He also set a world record in Moscow, on June 15, 1958, for 30 kilometers, running 1:32:58.8.

[3] Popov won the Soviet marathon title in 1957, when he ran the world's fastest marathon of the year in 2:19:50 in Moscow,[4] 1958 and 1959, and placed second in 1962 and third in 1963.

[5] In 1959, he set the course record at the Košice Peace Marathon, the third year in a row he ran the world's fastest time.

[4] He finished fifth at the 1960 Summer Olympics when the winner, Ethiopia's Abebe Bikila, broke Popov's world record by less than a second.