The Journal of the Siam Society (JSS) is a scholarly journal published by the Siam Society in Bangkok since 1904.

The Siam Society Under Royal Patronage 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 premises of the Society in Bangkok, Thailand on Asok Montri Road include a library with many rare books and the Kamthieng House Museum in a historic teak house. The Society has a regular programme of lectures, study trips, cultural events, and music performances. The Society publishes two scholarly journals, the Journal of the Siam Society and the Natural History Bulletin of the Siam Society, and several books. The Society is involved in preservation of heritage through the Siamese Heritage Trust. The membership includes people of around 60 nationalities.