The Royal Photographic Society of Great Britain, commonly known as the Royal Photographic Society (RPS), is the world's oldest photographic society having been in continuous existence since 1853. It was founded in London, England, in 1853 as the Photographic Society of London with the objective of promoting the art and science of photography, and in the same year, received royal patronage from then-Queen Victoria and Prince Albert.

A change to the society's name to reflect the patronage was, however, not considered expedient at the time. In 1874, it was renamed the Photographic Society of Great Britain, and only from 1894 did it become known as the Royal Photographic Society of Great Britain, a title which it continues to use today. On 25 June 2019, the Duchess of Cambridge, now Catherine, Princess of Wales, became the Society's Patron, taking over from Queen Elizabeth II who had been patron since 1952.

A registered charity since 1962, in July 2004, the society was granted a royal charter recognising its eminence in the field of photography as a learned society. For most of its history the Society was based at various premises in London; it moved to Bath in 1980 and since 2019 its headquarters has been in Bristol, England. Membership remains international and open to anyone with an interest in photography.

In addition to ordinary membership, the Society offers three levels of distinction—Licentiate, Associate and Fellow—which set recognised standards of achievement throughout the world, and can be applied for by both members and non-members, in all aspects of photography and vocational qualifications in the areas of creative industries and imaging science. The Society runs a programme of events throughout the United Kingdom and abroad, through local groups and special interest groups. The Society acts as a national voice for photographers and for photography more generally, and it represents these interests on a range of governmental and national bodies dealing with matters such as copyright and photographers' rights.

Photographers were slow in coming together and forming clubs and societies. The first was an informal grouping the Edinburgh Calotype Club around 1843. The first British photographic society, the Leeds Photographic Society was formed in 1852 but between 1878 and 1881 it ceased to exist independently. The RPS has existed continuously since January 1853. In other countries the Société héliographique was established in Paris in 1851 and the Société française de photographie was founded in Paris in 1854.

The catalyst behind the formation of The Photographic Society was Roger Fenton. The Great Exhibition of 1851 had raised public awareness of photography and in December 1852 an exhibition of nearly 800 photographs at The Society of Arts had brought together amateur and professional photographers. The inaugural meeting of The Photographic Society was held on 20 January 1853. Fenton became the Society's first secretary, a position he held for three years and Henry White was an early treasurer between 1866 and 1872.

As Jane Fletcher has argued the changing nature of photography and photographic education in the early 1970s forced The Society to modernise and to become more relevant to British photography. An internal review led to constitutional changes, the introduction of a new distinction called the Licentiate in 1972 and six new specialist groups were established.

The rising cost of maintaining The Society's premises in South Audley Street, London, eventually led the society's executive committee to look for alternative premises. The Council approved at a meeting on 1 April 1977 a move to Bath and the establishment of a National Centre of Photography to house the Society's headquarters and collection. An appeal for £300,000 was launched in the summer of 1978 for the funds needed to convert The Octagon and adjacent buildings in Milsom Street, Bath. The inaugural exhibition opened in May 1980 with the building officially opened by Princess Margaret in April 1981.