Teigue O'Rourke (Irish: Tadhg Ó Ruairc) (1576–1605) was the last king of West Breifne from 1603 until his death in 1605. He was the son of Brian O'Rourke and Mary Burke of Clanricarde. Raised by his mother in County Galway, he lived most of his life in exile from his kingdom, looking for allies to support his claim as king of West Breifne in opposition to his half-brother Brian Oge O'Rourke. Having initially supported the Irish alliance during the Nine Years' War, he switched allegiance to England following the Battle of Kinsale in 1602. With the support of English forces he invaded West Breifne in 1603, ousting his half-brother and ruling as king until his unexpected death in late 1605 at the age of 28.