Sergey Semyonovich Zorin (Russian: Сергей Семёнович Зорин, born Sergey Gumberg; 1890 – 10 September 1937), was the party's First Secretary of the Leningrad City Committee, roughly equating to that of mayor.

Sergey Semyonovich Gumberg was born in Ukraine.

[1] His father was a rabbi in Elizavetgrad and his brother, Alexander Gumberg emigrated to the United States in 1902.

He supported himself as an unskilled labourer before returning in March 1917 with Trotsky aboard the SS Kristianiafjord.

[1] He was married to Lisa Zorin, with whom he hosted Emma Goldman during her stay in Russia from January 17, 1920 to December 1921.