Serdobsk (Russian: Сердо́бск) is a town and the administrative center of Serdobsky District in Penza Oblast, Russia.

[10] It is located on the Serdoba River (Don's basin), 111 kilometers (69 mi) southeast of Penza.

The winter in Serdobsk is moderately cold and long lasting from the beginning of November to the end of March.

Summer is warm, lasting from late May to early September; the average July temperature is 20.4 °C.

Founded by Alexander Aleksandrovich of Penza in 1698, it has been known since 1699 as Serdobinskaya sloboda (Сердобинская слобода).