Sanjay Gandhi National Park is an 87 km (34 sq mi) protected area in Mumbai, Maharashtra. It was established in 1969 with its headquarters situated at Borivali.

The 2400-year-old Kanheri caves, sculpted by monks out of the rocky basaltic cliffs, lie within the park. The rich flora and fauna of the Sanjay Gandhi National Park attract more than 2 million visitors every year.

The Kanheri caves, located centrally in the park, were important Buddhist learning centres and pilgrimage sites sculpted by Buddhist monks between the 9th and the 1st centuries BCE. They were chiselled out of a massive basaltic rock outcropping. In 1996, the park was renamed to Sanjay Gandhi National Park, after Sanjay Gandhi. The same year, some forests from the Thane division were merged into the park, further expanding its total area to 103.84 km (40.09 sq mi).

The park occupies most of the northern suburbs of Mumbai. To the west lie the suburbs of Goregaon, Malad, Kandivali, Borivali and Dahisar. To the east lie the suburbs of Bhandup and Mulund. To the south lies the Aarey Milk Colony and the university campus of IIT Bombay. The northern reaches of this forest lie in Thane city. The park and the areas surrounding it, except Thane city, are all part of Mumbai. It is the only protected forest located within the limits of a city.

The region is hilly with elevations between 30 and 480 m (98 and 1,575 ft). Vihar Lake and Tulsi Lake in the park meet a part of the city's water requirements. The park is said to be the lungs of the city as it purifies much of the air pollution in the city.

This park is home to a number of endangered species of flora and fauna. The forest area of the park houses over 1,000 plant species, 251 species of migratory, land, and water birds, 5,000 species of insects, and 40 species of mammals. In addition, the park also provides shelter to 38 species of reptiles, 9 species of amphibians, 150 species of butterflies, and a large variety of fish.

In the state of Maharashtra, the mass flowering of karvi has been observed to occur in Mumbai in the same year as in the hill station of Khandala and one year earlier in Bhimashankar and Malshej Ghat, beyond Kalyan.

The forest cover in the park helps provide the ideal habitat for many wild animals. Chital, rhesus macaque and bonnet macaque are some of the wild mammals often spotted inside the park. Other large mammals found in the park include black-naped or Indian hare, muntjac (barking deer), porcupine, Asian palm civet, Small Indian civet, chevrotain, grey langur, Indian flying fox, sambar deer and leopard.

Reptiles living here include crocodiles in the Tulsi Lake, pythons, cobras, Checkered keelback, Common krait, monitor lizards, Russell's vipers, bamboo pit viper and Indian cat snakes.

In 2003, pugmarks and droppings of a Bengal tiger were found in the park. Although the tiger was never widely sighted, it did bring some excitement to city folks as records of tiger being found here are quite old and forgotten now with the last tiger being shot down 80 years earlier in the region. Conservation was also proposed for the interlinked habitat corridors and nearby forest areas in the state along with upgrading their status as tiger habitat.

A total 172 species of butterflies have been reported here, of which the spectacular ones are blue Mormon, the phenomenal artist of camouflage, blue oak leaf, bright Jezebel and large yellow and white orange tip, tiger butterfly, eggflies and sailers. There are a number of moths too. The largest moth is the size of a sparrow (30 cm).

Some of the birds in the park are jungle owlets, golden orioles, racket-tailed drongos, minivets, magpies, robins, hornbills, bulbuls, sunbirds, peacock, and woodpeckers. Migratory and local birds such as the paradise flycatcher and various species of kingfishers, mynas, drongos, swifts, gulls, egrets, and herons have also been spotted.

The park has faced a number of problems similar to those faced by national parks elsewhere in the world, involving conflicts between natural and human interests.

In June 2004, leopards were responsible for the deaths of 20 humans within the span of a week. This was not the first attack: for the past 10 years, there have been attacks attributed to leopards stalking children and adults outside the park fringes. After an outcry was raised and the situation reached alarming proportions, eight leopards were caught and relocated.

The leopard threat still continues in and around the Thane district today, with repeated sightings as well as attacks on pets and humans. On 16 July 2012, a seven-year-old girl was killed in Mulund right outside her home by a leopard. A year later, a 40-year-old woman was attacked and killed by a leopard in Bhiwandi, Thane City, in 2013. Five days later, a 14-year-old shepherd survived a leopard attack in the same region. In 2014, a two-year-old child went missing from Ghoong village in Wada. August 2015 saw four leopard attacks in Thane city. In one incident, a leopard and her cub dragged a one-year-old Rottweiler off.

• Patwardhan, A. (2014). Butterflies of Sanjay Gandhi National Park, Mumbai, Maharashtra, India. Ambient Science 1(1): 7–15.
• Kasambe, R. (2012): Butterfly fauna of the Sanjay Gandhi National Park and Mumbai. Bionotes 14 (3): 76–80.

• Official website
• SGNP link on Maharashtra FD Website Archived 29 July 2013 at the Wayback Machine of "Sanjay Gandhi National Park Borivali, Mumbai 400066".