Damyan Yovanov Gruev (Bulgarian: Дамян Йованов Груев, Macedonian: Дамјан Јованов Груев), (originally spelled in pre-1945: Bulgarian orthography Дамянъ Йовановъ Груевъ), (January 19, 1871 – December 23, 1906) was а Macedonian Bulgarian teacher, revolutionary and insurgent leader in Ottoman regions of Macedonia and Thrace. He was among the founders of the Internal Macedonian Revolutionary Organization (initially known as the Bulgarian Macedonian-Adrianopolitan Revolutionary Committee). Despite his Bulgarian self-identification, according to the post-World War II Macedonian historiography, he was an ethnic Macedonian.