Michael Joseph McGrath (24 March 1882 – 28 February 1961) was an Irish-born prelate of the Roman Catholic Church. He served first as the Bishop of Menevia from 1935 to 1940, then the Archbishop of Cardiff from 1940 to 1961.
Born in Kilkenny, Ireland on 24 March 1882, educated locally by the Christian Brothers and at Rockwell College (earning a BA from the Royal University of Ireland). After training for the prieshood in St. John’s College, Waterford, he was ordained to the priesthood on 12 July 1908. He was appointed the Bishop of the Diocese of Menevia on 10 August 1935. His consecration to the Episcopate took place on 24 September 1935, the principal consecrator was Archbishop Francis Mostyn of Cardiff, and the principal co-consecrators were Bishop William Lee of Clifton and Bishop Ambrose James Moriarty of Shrewsbury. Five years later, McGrath was translated to the Archdiocese of Cardiff as archbishop on 20 June 1940. He was awarded an honorary D.Litt by the National University of Ireland. He died in office on 28 February 1961, aged 78.