Máirtín Ó Cadhain (; 1906 – 18 October 1970) was one of the most prominent Irish language writers of the twentieth century. Perhaps best known for his 1949 work "Cré na Cille", Ó Cadhain played a key role in bringing literary modernism to contemporary Irish language literature. Politically, he was an Irish nationalist and socialist, promoting the "Athghabháil na hÉireann" ("Re-Conquest of Ireland"), through Gaelic culture. He was a member of the post-Civil War Irish Republican Army with Brendan Behan during the Emergency.