BAPS Shri Swaminarayan Mandir (also commonly known as the Neasden Temple) is a Hindu temple in Neasden, London, England. Built entirely using traditional methods and materials, the Swaminarayan mandir has been described as being Britain's first authentic Hindu temple. It was also Europe's first traditional Hindu stone temple, as distinct from converted secular buildings. It is a part of the Bochasanwasi Shri Akshar Purushottam Swaminarayan Sanstha (BAPS) organisation and was inaugurated in 1995 by Pramukh Swami Maharaj. The temple complex also consists of a permanent exhibition entitled "Understanding Hinduism" and a cultural centre housing an assembly hall, gymnasium, bookshop, and offices.

The BAPS Shri Swaminarayan Mandir is located on Pramukh Swami Road, Neasden, London. The mandir is close to the North Circular Road, and can be reached by bus or on foot from Wembley Park, Stonebridge Park, Harlesden, and Neasden Underground and Overground stations. The complex is 102,018 square feet and includes the first traditional stone mandir in Europe adjoined with a cultural center, and a 550-car parking lot. At the time of its completion, the mandir became the largest Hindu mandir built outside of India. The cultural center includes a foyer, a prayer hall, a conference hall, an exhibition hall, a marriage hall, a sports hall, a library, and a health clinic.

In August 2020, to commemorate the 25th anniversary of the mandir's opening, King Charles III and Queen Camilla said that, "the first of its kind outside India, Neasden Temple serves the local community as a place of worship, learning, celebration, peace and community service." The King and Queen had previously visited the temple in 2009 for the traditional festival of Holi.

The mandir rises to a height of 21 meters (70 feet) and is 60 meters (195 feet) long. The exterior of the mandir covered with 990 cubic meters (35,000 cubic feet) of Bulgarian limestone, while the interior of the mandir is composed of 700 cubic meters (25,000 cubic feet) of Indian and Italian marble. The mandir covers 1.5 acres of land and is made up of over 1,699 cubic meters (60,000 cubic feet) of stone, without the use of ferrous materials like steel. The mandir includes 7 shikhars (pinnacles), 6 gummats (domes), 193 sthambhas (pillars), 32 gavakshas (windows), and 4 jharukhas (balconies). The central dome is 10 meters high and the design was inspired by the Delwara Jain Mandir in Mount Abu, Rajasthan. The mandir has over 500 unique designs, 26,300 carved stone pieces, and 55 different ceiling designs. In its September 2000 edition, the National Geographic referred to the mandir as "A London Landmark."

The haveli, built in a traditional haveli style, has a courtyard architectural style that was originally developed in 17th century western India, and serves as a cultural center for the mandir. The traditional haveli design highlights specific architectural components like the façade, open courtyards, carved columns, arches, doors, windows, and balconies.

Adjoining the mandir is BAPS Shri Swaminarayan Haveli, a multi-function cultural centre. Whereas the mandir is carved from stone, the haveli is constructed from wood. English oak and Burmese teak have been fashioned into panels, arches and screens, all carved by craftsmen in India with a cornucopia of geometric patterns, stylised animal heads, and flower garlands.

The Burmese teak used was harvested from sustainable forests. To compensate for the 226 English oak trees used, over 2,300 English oak saplings were planted in Devon. The haveli also incorporates energy-saving features such as light-wells.

Richly carved haveli-style woodwork from Gujarat is the most striking characteristic of the building's façade and foyer. It has been designed according to traditional Indian haveli architecture, to evoke feelings of being in Gujarat, India, where such havelis were once commonplace. It required over 150 craftsmen from India three years to carve 1,579 m² (17,000 square feet) of wood. Behind the traditional wooden façade, the cultural centre houses a vast pillarless prayer hall with space for 3,000 people, a gymnasium, medical centre, dining facilities, bookstall, conference facilities, and offices.^{[citation needed]}