Máel Ruain was an eighth-century Irish priest, abbot, and bishop who established the monastery at Tallaght in County Dublin. As a central figure in the Céli Dé monastic movement, he emphasized communal living and strict spiritual discipline. Although specific details regarding his early life remain uncertain, he is remembered as a significant teacher whose monastic principles influenced many followers. His leadership helped shape a distinct tradition of asceticism in Ireland, characterized by a focus on the Psalter and the rejection of worldly distractions.