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.
He was among the first entomologists to investigate mimicry and polymorphism in butterflies and their restriction to females.
He also collaborated with Charles Darwin to study the pollination of Disa orchids.