Kolkata Circular Railway, also known as the Kolkata Chakra Rail, is a 36.20 km (22.49 mi) long railway loop line operated by the Sealdah division of the Eastern Railway zone of Indian Railways, encircling the city of Kolkata.

Sealdah railway division is one of the four railway divisions under the Eastern Railway zone of the Indian Railways. Its headquarters is located in Kaiser Street in Kolkata, West Bengal near the Sealdah railway station. Geographically the division covers the railway tracks and services in the areas between the Hooghly river on the west, Bangladesh on the north and east and the Sundarbans in the south.