Kasimov is a Russian town, the administrative center of the Kasimov District of the Ryazan Region. It is located on the left bank of the Oka River.
The town with the population of 31 897 people (as of 2014) takes the area of 32 sq km.
It is located in the eastern part of Meshchora Lowland. It is 8 km away from the railway station, and 156 km to the north-east of Ryazan. It is a river pier.