Serhiy Fedorovych Tkach (Ukrainian: Сергій Федорович Ткач, Russian: Серге́й Фёдорович Ткач; 15 September 1952 – 4 November 2018), also known as Sergey Tkach, was a Russian-born Ukrainian police officer and serial killer who was convicted for the killings of thirty-seven women and girls in the Soviet Union and later Ukraine between 1980 and 2005.

Serhiy Tkach was born on 15 September 1952, in Kiselyovsk, Kemerovo Oblast, Russian SFSR, Soviet Union.

Tkach worked as a police investigator in Kemerovo Oblast, where he was recommended for admission to a Ministry of Internal Affairs school until he was caught falsifying evidence and forced to resign.

[2][4] In 2008, after a yearlong trial, Tkach was sentenced to life imprisonment for the murder of thirty-seven women and girls over more than two decades.

[2] Over the years, fifteen men had been wrongly jailed for some of the murders of which Tkach was found guilty, one of whom committed suicide, and another was not released until March 2012.