Thomas Barrett (; died ) was a fifteenth-century Bishop of Annaghdown.
Barrett obtained a papal provision to the see of Annaghdown on 17 April 1458 and acted as a suffragan bishop in the English dioceses of Exeter (1458; 1468âÂÂ75) and Bath and Wells (1482âÂÂ85).
According to Cotton, Barrett was also a canon of York Minster; holding the Prebendary of Laughton (1466âÂÂ67).
Barrett died sometime after 1485.