The Siam Society Under Royal Patronage (Thai: สยามสมาคมในพระบรมราชูปถัมภ์; S̄yām s̄mākhm nı phrabrm rāchūpt̄hạmp̣h̒) was established in 1904 with a mission to promote knowledge of the culture, history, arts, and natural sciences of Thailand as well as those of neighbouring countries.

The Center undertook pioneering research on archaeology, zoology, and the anthropology of minority communities including the Phi Tong Luang or Mlabri people.

In 1931, Ahamad Ebrahim Nana, a businessman of Indian origin born in Thonburi, gifted the Society 3 rai (0.48 hectare) of land on the outskirts of Bangkok.

A building, consisting largely of an auditorium and library, was designed by Edward Healy, a British architect, and officially opened on 28 February 1933.

The teakwood house was originally built in Chiang Mai, in the mid-19th century, on the east bank of the Ping River by Mae Saed, a great-granddaughter of a prince of Mueang Chae.

The structure consists of two prefabricated rectangular units with a common floor, a covered veranda and walkway leading to the kitchen, and an open platform – all elevated on 36 octagonal teak pillars.

The walls lean slightly outward from the floor to the lower edge of the peaked roof, the end of which are adorned with v-shaped galae.

In 1988, on the occasion of the Society's 84th anniversary, and also in commemoration of her late husband Acharn Saeng Aroon, Khun Lada Ratkasikorn gifted a teakwood house, an excellent example of central Thai architecture.

[14] Lectures are given in English on an almost-weekly basis, held on weekday evenings, by authors, visiting scholars, leading experts and enthusiasts.

In 1988–89, the Society undertook restoration of the traditional northeastern-style murals in Wat Sra Bua Kaew in Khon Kaen Province.

The collection of rare books assembled by ML Manich Jumsai, including early European works on Siam and the papers of Prince Prisdang, are kept in the library.

The Orchids of Thailand: A Preliminary List, by Gunnar Seidenfaen and Tem Smitananad, published in six volumes between 1959 and 1965, is recognized as the authoritative work on the subject.

The Natural History Bulletin of The Siam Society (NHBSS) is a biannual publication of scholarly articles in English on the flora and fauna of Thailand and neighbouring countries.

The President and Council are elected by life and ordinary members attending the Annual General Meeting, and serve for terms of two years.

[26] In 1990, the Society launched a project to cast a gold Footprint of Lord Buddha based on a wax model made at the time of King Chulalongkorn in honour of the 60th birthday of Queen Sirikit.

The Footprint, using 35 kilograms of gold and measuring 170 x 70 centimeters, was cast in Thonburi, and consecrated by King Bhumibol Adulyadej in a ceremony at Wat Phra Kaew on 22 June 1994.