MacRory is one of ten children of Francis MacRory, a farmer, and his wife, Rose Montague. He studies at St. Patrick’s College, Armagh, and St. Patrick’s College in Maynooth. He is ordained to the priesthood on September 13, 1885 and serves as the first president of St. Patrick’s Academy, Dungannon from 1886 to 1887. MacRory teaches Scripture and Modern Theology at St. Mary’s College, Oscott in England until 1889, when he is appointed Professor of Scripture and Oriental Languages at his alma mater of Maynooth College. In 1906, he co-founds the Irish Theological Quarterly. In 1912, he is made Vice-President of Maynooth.
On August 9, 1915, MacRory is appointed Bishop of Down and Connor by Pope Benedict XV and receives his episcopal consecration on November 14 from Cardinal Michael Logue. During his tenure, his life is threatened repeatedly due to the turbulent atmosphere in Belfast. He is a member of the Irish Convention from 1917 to 1918.
MacRory is promoted to Archbishop of Armagh and thus Primate of All Ireland on June 22, 1928, in succession to Patrick O’Donnell. He is elevated to the cardinalate on December 16, 1929, by Pope Pius XI.
MacRory is the papal legate at the 1933 laying of the foundation stone of Liverpool Metropolitan Cathedral in England. He also serves as one of the cardinal electors who participate in the 1939 papal conclave which ultimately selects Pope Pius XII.
MacRory is a strenuous opponent of social injustice, National Socialism, Protestantism, and the Partition of Ireland. It is MacRory who suggests to Eoin O’Duffy that he raise an Irish Brigade to aid Generalissimo Francisco Franco during the Spanish Civil War. In 1940, he voices strong objections to conscription in the North.
MacRory is a supporter of the Gaelic League. Errigal Ciarán GAC, one of the most famous GAA clubs in Ireland, plays at Cardinal MacRory Park in Dunmoyle, County Tyrone, which is built in 1956 in his honour.
After a brief illness, Cardinal MacRory dies on October 13, 1945, at the age of 84 from a heart attack at Ara Coeli, the residence in Armagh. He is interred in St. Patrick’s Cathedral Cemetery, Armagh.