O'Donnell (Irish: Ó Dónaill or Ó Domhnaill), which is derived from the forename Domhnaill (meaning "world ruler", Rex Mundi in Latin, Modern Irish spelling, Dónall) were an ancient and powerful Irish family, kings, princes, and lords of Tír Chonaill (rendered in English as Tyrconnell or Tyrconnel, known today as County Donegal) in early times, and the chief allies and sometimes rivals of the O'Neills in Ulster.

Like the family of O'Neill, that of O'Donnell of Tyrconnell was of the Uí Néill, i.e. descended from Niall of the Nine Hostages, High-King of Ireland at the beginning of the 5th century; the O'Neill, or Cenél nEógain, tracing their pedigree to Eógan mac Néill, and the O'Donnells, or Cenél Conaill, to Conall Gulban, both sons of Niall. Conall was baptised by St. Patrick.

The Byzantine Emperor, Constantine the Great, converted to Christianity after a vision before the famous Battle of the Milvian Bridge, having seen a chi-rho in the sky, and thence the motto In Hoc Signo Vinces, telling him he would be victorious with the sign of the cross. The chi-rho was adopted on a banner, the labarum, upheld on a vexillum, which resembled a Christian cross, and in time the motto became associated with the Cross all over Europe. Legend has it that St. Patrick struck the shield of Conall, son of King Niall of the Nine Hostages, with his crosier, called Bachall Isa (the staff of Jesus) inscribing thereon a sign of the cross and told him the same, and baptized him. This legend is described in the Lebhar Inghine i Dhomhnaill. His land became Tír Chonaill, Tyrconnell, the land of Conall.

Lawrence Francis O'Donnell, Jr. (born November 7, 1951) is a political analyst, journalist, actor, producer, writer, and host of The Last Word with Lawrence O'Donnell, a weeknight MSNBC opinion and news program. O'Donnell called himself a "practical European socialist" in a Newsmaker Interview dated November 11, 2005. He frequently filled in as host of Countdown before getting his own show on the cable network. Beginning 24 October 2011, The Last Word with Lawrence O'Donnell switched time slots with The Ed Show, with Ed Schultz taking over the 8 p.m. Eastern slot, and O'Donnell returning to the 10 p.m. Eastern slot.

O'Donnell has also appeared as a political analyst on The McLaughlin Group, The Al Franken Show, and Countdown. He was an Emmy Award-winning producer and writer for the NBC series The West Wing and creator and executive producer of the NBC series Mister Sterling. He is also an occasional actor, appearing as a recurring supporting character on the HBO series Big Love, portraying an attorney. He began his career as an aide to U.S. Senator Daniel Patrick Moynihan and was Staff Director for the Senate Finance Committee.

Anthony David Weiner (pronounced /ˈwiːnər/; born September 4, 1964) is a former U.S. Representative who served New York's 9th congressional district from January 1999 until June 2011. A Democrat, Weiner held the seat previously occupied by Democrat Charles Schumer and won seven terms, never receiving less than 59 percent of the vote. He was an unsuccessful candidate for mayor of New York City in the 2005 election, and had begun to amass a campaign fund to run again for mayor in 2013.

Previously, Weiner was a New York City councilman from 1992 to 1998, and a congressional aide to then-U.S. Representative Schumer from 1985 to 1991. A New York City native, he attended the public schools and graduated from the State University of New York at Plattsburgh in 1985 with a bachelor of arts degree in political science.

Weiner resigned from Congress due to a sexting scandal, effective June 21, 2011. A special election was held on September 13, 2011, to fill the remainder of his term.

Weiner was born in Brooklyn, New York, one of three sons of Mort Weiner, a lawyer, and his wife Fran, a public high school mathematics teacher. The family lived for a time in the Park Slope neighborhood of Brooklyn. Weiner described his ethnic and religious background in 2011: "We weren't a very religious household," he said, "but we had a very strong sense of our Judaism." His older brother, Seth, was killed at age 39 in a hit-and-run vehicle-pedestrian accident in May 2000. His younger brother, Jason, is a chef and co-owner of several New York restaurants.

Majella O'Donnell (nee McClelland) is a businesswoman, singer, reality television star and the wife of entertainer Daniel O'Donnell. She is a native of Thurles, County Tipperary.

Herself and Daniel appeared together on The Late Late Show in the edition presented by Gerry Ryan in the absence of Pat Kenny on 24 October 2008. She has described him as a practical joker who hides in the closet if they have an argument. In January 2009, she featured without him as an advisor to Dana Rosemary Scallon on The All Ireland Talent Show. She managed Lissan in the fourth season of Celebrity Bainisteoir after Dana left to contest the 2011 Irish presidential election.

She has spoken of her ongoing battles with depression. She released an album in 2011.

Daniel Francis Noel O'Donnell (born 12 December 1961) is an Irish singer, television presenter and philanthropist. O'Donnell came to public attention in 1983 and has since become a household name in Ireland and the UK. He has also had considerable success in the US and Australia. He is known for his close relationship with his fanbase, and his charismatic and engaging stage presence. His music has been described as a mix of country and Irish folk, and he has sold over ten million records to date. O'Donnell is also known for his tenor voice. In Ireland, he is widely considered a 'cultural icon', and is often parodied in the media. He is a prominent ambassador for his home county of Donegal, and he is affectionately known as 'Wee Daniel'.

O'Donnell was born and brought up in the village of Kincasslagh, in the Rosses region of County Donegal. He grew up as the youngest of a Roman Catholic family, with his parents Julia (née McGonagle born 1919) and Francis O'Donnell and his siblings: John (the eldest), Margaret (Margo), Kathleen, and James. He has described his upbringing as mostly happy, with the exception of the death of his father after a heart attack when O'Donnell was just six years old.