Gottfried Reinhold Treviranus (4 February 1776 – 16 February 1837) was a German naturalist. He was a proponent of the theory of the transmutation of species, a theory of evolution held by some biologists prior to the work of Charles Darwin. He put forward this belief in the first volume of his Biologie; oder die Philosophie der lebenden Natur, published in 1802, the same year similar opinions were expressed by Jean-Baptiste Lamarck.
Treviranus was born in Bremen and studied medicine at Göttingen, where he took his doctor's degree in 1796. In 1797 he was appointed professor of medicine and mathematics at the Bremen lyceum. In 1816, he was elected a corresponding member of the Royal Swedish Academy of Sciences.
His younger brother, Ludolph Christian Treviranus (1779–1864) was a botanist.