Marion & Company, usually styled Marion & Co., was a London-based photographic firm with roots in early 19th century France. Its origins trace back to around 1835, when Claude Mames Augustin Marion established a stationery business in Paris. The company was known as Auguste and Augustin Marion interchangeably. Around 1842, at the dawn of the photographic age, Marion opened a London branch of Marion & Co., initially importing and selling French stationery.

By 1854, with premises on Regent Street, Marion & Co. had begun to stock papers designed for photographic use, such as salted and albumen types, alongside traditional stationery. In 1866, the company opened a warehouse and showroom at Soho Square. The following year, Claude Marion retired as head of Auguste Marion & Co. and a new company, Marion & Co., was formed under the control of three partners: Auguste Leon Marion, Henry Edward Géry, and George Bishop.

During the 1880s, Marion & Co. expanded into manufacturing photographic equipment and materials, including cameras and studio apparatus. In 1886, it opened a dedicated factory in Southgate, Middlesex, producing photographic paper, plates, and later, roll-film cartridges. As photography gained popularity among the general public, Marion & Co. increasingly targeted amateur photographers. The publication of Marion's practical guide to photography (1884) catered to this growing market.

By the late 1890s, the company was managed by Auguste Leon Marion, Henri Louis Guibout, George Bishop, Frank Bishop, and John Pattinson Kirk. The partnership was dissolved in 1901, and the business continued as a limited company. In 1921, Marion & Co. Limited was absorbed, along with six other companies, into Amalgamated Photographic Materials (APM), ending its existence as an independent entity. In 1929, AGM split off the photographic product lines of Marion, Paget and Rajar divisions into a new entity called Amalgamated Photographic Equipment Materials (APeM). Shortly thereafter, ApeM was incorporated into the Ilford group.