Roland Trimen FRS (29 October 1840 in London – 25 July 1916 in London) was a British-South African entomologist, 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.