South 24 Parganas (Pron: pɔrɡɔnɔs; abbr. 24 PGS (S)), or sometimes South Twenty Four Parganas and Dakshin 24 Parganas, is a district in the Indian state of West Bengal, headquartered in Alipore. It is the largest district of West Bengal by area and second largest by population. It is the sixth most populous district in India (out of 640). On one side of the district there is the urban fringe of Kolkata, and on the other the remote riverine villages in the Sundarbans.

Sundarbans is a mangrove area in the delta formed by the confluence of the Ganges, Brahmaputra and Meghna Rivers in the Bay of Bengal. Spread across parts of India and Bangladesh, this forest is the largest mangrove forest in the world. It spans the area from the Baleswar River in Bangladesh's division of Khulna to the Hooghly River in India's state of West Bengal. It comprises closed and open mangrove forests, land used for agricultural purpose, mudflats and barren land, and is intersected by multiple tidal streams and channels. Sundarbans is home to the world's largest area of mangrove forests. Four protected areas in the Sundarbans are enlisted as UNESCO World Heritage Sites, viz. Sundarbans West (Bangladesh), Sundarbans South (Bangladesh), Sundarbans East (Bangladesh) and Sundarbans National Park (India).