Máel Dithruib was an Irish anchorite of Terryglass (Tír-dá-Glass) in Tipperary who died in 840, the chief disciple and conversation-partner of Máel Ruain of Tallaght in the Céli Dé reform. The document called the Monastery of Tallaght, recording the customs and teaching of that church, is essentially a memoir of his and his master’s practice.