Kostinbrod (Bulgarian: Костинброд) is a town in western Bulgaria. It is located 15 km west of the capital city of Sofia. It is located on two important transport corridors: Lom — Sofia — Thessaloniki and Sofia — Belgrade. The international railway line to Western Europe passes through the municipality, with a train stop at Kostinbrod Station.

The town is crossed by two rivers, the Blato in the north and the Belitsa in the south, both tributaries of the Iskar River.

According to the legends, the town was founded by a certain Kosta, who settled near the crossing (брод, brod) of the Belitsa, thus giving the name to the town (Kostinbrod means "Kosta's ford"). There he opened a pub that became popular among the merchants arriving in the capital, some of them settling and organizing a village, whose centre of the time is now located west of the road between Sofia and Lom. Historically, an early reference to the locality (as КОСТИНЪ БРОДЪ) can be found in Tsar Ivan Alexander of Bulgaria's Oryahov Charter of 1 December 1348.