Main article: Irish personal naming system
|Male||Daughter||Wife (Long)||Wife (Short)|
|Mac Donnchadha||Nic Dhonnchadha||Bean Mhic Dhonnchadha||Mhic Dhonnchadha|
- Thomas MacDonagh (1878–1916), Irish nationalist poet, playwright, and a leader of the 1916 Easter Rising
- Bill McDonagh (1928), is a former professional ice hockey left winger.
- Brendan McDonagh is the Managing Director of the National Asset Management Agency in the Ireland.
- Charlotte McDonagh (1984 in Edgware, London, England), is a British actress.
- Donagh MacDonagh (1912–1968), Irish writer and judge (son of Thomas below).
- Eileen MacDonagh, Irish sculptor, active from the 1980s.
- Enda McDonagh is a priest of the Roman Catholic Archdiocese of Tuam.
- Jacko McDonagh (1962, Dublin), was an Irish professional footballer.
- Jarlath McDonagh (1945), is a Fine Gael politician from County Galway in Ireland.
- Jay McDonagh (born 1973), American football player
- Jim McDonagh (1952, Rotherham, England), nicknamed Seamus, is currently goalkeeping coach at Aston Villa.
- Joseph MacDonagh (died 1922), Irish Sinn Féin politician (brother of Thomas).
- Joe McDonagh (1953, Ballinderreen, County Galway), is a retired Irish sportsman
- John McDonagh (1880–1961) was an Irish film director (brother of Thomas MacDonagh)
- Maitland McDonagh, is an American film critic and the author of several books about cinema.
- Margaret McDonagh, Baroness McDonagh, is a British Labour Party politician and was General Secretary of the Labour Party from 1998 to 2001 (sister of Siobhain).
- John Michael McDonagh (1967) is a contemporary English-born Irish screenwriter and film director.
- Martin McDonagh (1970) is a contemporary English-born Irish playwright and film director.
- Mike McDonagh is a humanitarian, and a senior United Nations official working for the United Nations Office for the Coordination of Humanitarian Affairs.
- Monika MacDonagh-Pajerová (1966 - ), Czech academic.
- Paul McDonagh (1945), is a retired American professor and currently a senior amateur golfer in Tucson, Arizona.
- Pat McDonagh is the founder of Supermac's.
- Peter McDonagh in Galway, Ireland is a professional boxer.
- Philip McDonagh is an Irish footballer currently playing for Bohemians in the League of Ireland.
- Ryan McDonagh (1989, Arden Hills, Minnesota) is a professional ice hockey defenceman.
- Siobhain McDonagh (1960, London), is a British Labour Member of Parliament for the Mitcham and Morden constituency in London (sister of Margaret).
- Stephen McDonagh (1970, Bruree, County Limerick), is a retired Irish sportsperson.
- Willo McDonagh (1983, Dublin), is an Irish footballer currently playing for Glenavon F.C.
- Kilruane MacDonagh's GAA club is located in the areas of Kilruane and Cloughjordan, ten miles from Nenagh in north County Tipperary, Ireland.
- Thomas MacDonagh's GFC is a Gaelic football club in County Tipperary.