Clonfert Cathedral is a cathedral of the Church of Ireland in Clonfert, County Galway in Ireland. It is in the ecclesiastical province of Dublin. Previously the cathedral of the Diocese of Clonfert, it is now one of three cathedrals in the United Dioceses of Limerick and Killaloe.
The current building was erected in the 12th century at the site of an earlier 6th century church founded by Saint Brendan, which was associated with a monastery he founded and at which he was buried. The Dean of the Cathedral is the Very Reverend Gary Paulsen who is also Dean of Killaloe, Dean of Kilfenora and both Dean and Provost of Kilmacduagh.