Diamond Harbour (Bengali: [ˈɖai̯mənɖ ˈɦaɾbaɾ] ⓘ) is a city and a municipality of South 24 Parganas district in the Indian state of West Bengal.

[5] There was a fort named Chingrikhali Kella, reportedly built by Portuguese pirates during 1600s, presently dilapidated.

The entire district is situated in the Ganges Delta and the western part, located on the east bank of the Hooghly River, is covered by the Kulpi Diamond Harbour Plain, which is 5–6 metres above sea level.

Archaeological excavations at Deulpota and Harinarayanpur, on the bank of the Hooghly River indicate the existence of human habitation more than 2,000 years ago.

It had a population density of 4,035 inhabitants per square kilometre (10,450/sq mi) with a sex ratio of 986 females for every 1000 males.

Diamond Harbour had a total of 10,048 households as per report released by 2011 Census of India.

[16] According to the 2011 Census of India, 85.98% of the population is Hindu, 13.75% Muslim, 0.11% Christian, 0.10% Sikh, 0.01% Buddhist and 0.01% Jain.

[18][19] Diamond Harbour police station covers an area of 134 km2 (52 sq mi).

After the partition of India, refugees from East Pakistan/ Bangladesh had a strong impact on the development of urban areas in the periphery of Kolkata.