Roland Trimen FRS (29 October 1840 in London – 25 July 1916 in London) was a British-South African naturalist, best known for South African Butterflies (1887–89), a collaborative work with Colonel James Henry Bowker.
Trimen arrived at the Cape in 1859, taking up a post in the Auditor-General's office in Cape Town and then transferred to the office of the Colonial Secretary. In 1872 he became curator of the South African Museum in Cape Town, succeeding Edgar Leopold Layard. He attended the international congress on Phylloxera in Bordeaux in 1880. Failing health caused him to resign his position at the South African Museum in 1893.
Trimen also described a new species of bird, the Racket-tailed roller, based on skins provided to the South African Museum.
Trimen won the Darwin Medal of the Royal Society in 1910 and was the director of the South African Museum of Cape Town. Trimen was born the son of Richard and Mary Ann Esther Trimen and was the elder brother of Henry Trimen, botanist and director of the botanical gardens at Peradeniya, Ceylon.
Roland Trimen in libraries (WorldCat catalog)