Matthew "Mattie" McDonagh (1936 – 11 April 2005) was an Irish Gaelic footballer who played for his local club Ballygar and at senior level for the Galway county team from 1956 until 1968.
After the initial flush of success some lean years followed and Mattie had to bear the disappointment of two county final defeats with Ballygar at the hands of Tuam Stars and Dunmore McHales, the later by the narrowest of margins but the best was yet to come.
After Galway had been beaten by Dublin in the 1963 All-Ireland Senior Football Championship Final, when Gerry Davey scored the controversial winning goal, the county under the stewardship of John Dunne, was to embark on their greatest ever run of success, winning three All-Ireland titles, beating Kerry in the first two and Meath in 1966 to complete the three-in-a-row, where Mattie McDonagh will be forever remembered in firing home ’left footed’ the only goal of the match in a 1–10 to 0–7 victory.
He never shirked a challenge and took on the task of managing the Galway senior team in 1980 after a turbulent period when player power made the headlines in the county and a cool and respected head was needed to settle the ship.
One year later he led Galway to what turned out to be their last National League success when routing Roscommon in the Croke Park final although their semi-final victory over Kerry in Ennis was the real highlight of that series.