Sierpc [ɕerpt͡s] is a town in Poland, in the north-west part of the Masovian Voivodeship, about 125 km northwest of Warsaw. It is the capital of Sierpc County. Its population is 18,777 (2004). It is located near the national road No 10, which connects Warsaw and Toruń. Sierpc is a rail junction of local importance, where two lines cross: Kutno - Brodnica, and Nasielsk - Toruń.