Diamond Harbour is a well-known place situate in the southern suburbs of Kolkata (Calcutta), West Bengal state of India. Located on the banks of the river Hooghly, it is a popular weekend tourist spot in the city of Kolkata.

Earlier Diamond Harbour was known as Hajipur and later on the name was changed by the British, as it was once used as a major port during their reign.

Just near the Diamond Harbour, the remains of a Portuguese fort is seen which is believed to have been the hideout of the pirates from Portugal.