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George Clooney - The actor, director, producer, and activist's Irish ancestors on his father side were small farmers from Windgap, County Kilkenny.

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Tom Brady - The star quarterback is a direct descendant of Irish immigrants who landed in Boston during the height of the Great Famine in the mid-19th century.

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Johnny Depp - The actor’s connection to Ireland comes from his mother. He has often spoken about his wish to explore his Irish ancestry and learn more about his roots.

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Christina Aguilera - The singer’s Latin American heritage has drawn more attention potentially because of her last name, but her mother is Irish-American.

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Lindsay Lohan - The actress’ maternal antecedents were Irish Catholic stalwarts, and her great-grandfather, John L. Sullivan, was a co-founder of the Pro-life Party in Long Island.

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Chris Evans - The actor best known for his role as Captain America is Irish on his mother’s side, as she is half Italian and half Irish. He and his sibling were raised Catholic.

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Robert Downey Jr. - The actor’s father is a quarter Irish, which makes Iron Man 12.5% Irish.

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Rosario Dawson - The actress’ Puerto Rican and Cuban heritage are well known, but Dawson’s biological father was of Irish descent. He wasn’t very involved in Dawson’s life, however, which might explain why she doesn't address her Irish heritage as often.

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Jimmy Fallon - The host and comedian’s paternal great-great-grandfather hailed from County Galway.

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Sean Penn - The actor is Irish on his mother’s side. His great-grandfather was Irish-born, while his great-grandmother’s parents were Irish, so he’s distantly Irish at this point.

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Joe Biden - The President's origins trace back to County Louth, a land Biden’s great-grandfather, James Finnegan, left behind in 1850.

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Grace Kelly (1929-1982) - The actress-turned-Princess-of-Monaco was the daughter of John B. Kelly Sr., an accomplished rower whose parents hailed from Newport, County Mayo, Ireland, and arrived in Philadelphia in 1869.

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Barack Obama - America’s first African-American president is also part Irish. His family on his mother’s side has roots that trace back to a small village in Moneygall, County Offaly. They immigrated to the US in the 1850, at the height of the Great Famine.

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Elijah Wood - The actor is 25% Irish on his father’s side. He also has English, German, Danish, and Austrian heritage.

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Billy the Kid (1859-1881) - Not only was one of America’s most infamous outlaws of Irish descent, he also spoke Gaelic and often translated for those who had yet to learn English. His real name is supposed to have been Henry McCarthy.

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Mariah Carey - The diva's mother was born and raised in Illinois, but her parents were Irish emigrants from Cork.

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Alicia Keys - The singer has a rich heritage, including being African American, Italian, and Irish (on her mother’s side).

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Jennifer Connelly - The actress is Irish on her father’s side, who is part Irish and part Norwegian.

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Olivia Wilde - The actress and director has strong connections to Ireland, including citizenship. Her father, an Englishman born in London, was raised in Ireland. Wilde spent her summers growing up in Ardmore, County Waterford.

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Richard Nixon (1913-1994) - The former President’s ancestry traces back to Ballymoney, County Antrim, and Carrickfergus, County Antrim, though his Irish family member immigrated to the US in the 18th century.

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Danica Patrick - The first female racer to take pole position at the Daytona 500 descends from Irish ancestry on her father's side.

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Muhammad Ali (1942-2016) - The legendary boxer’s roots trace back to Ennis, County Clare, south of Galway on the west coast. His maternal great-grandfather before settled in Kentucky where he married Ali’s great-grandmother, who was a former slave.

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Mel Gibson -

The actor is Irish on both sides. His mother was born in County Longford, Ireland, while his paternal grandmother was born in Australia to Irish parents.

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Kurt Cobain (1967-1994) -

The 1990s icon was of Irish descent on his father’s side, whose family—originally named “Cobane”—emigrated from Carrickmore, County Tyrone, in 1875 where they worked as shoemakers.

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Mark Wahlberg - The actor had an Irish-Catholic upbringing, as he is of Irish descent on both sides. At least part of his family hails from County Donegal.

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Judy Garland (1922-1969) - The actress and singer was of Irish descent on her mother’s side. Her maternal grandmother was the daughter of a Dubliner and an Irish-Canadian.

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Bruce Springsteen - The singer-songwriter’s roots trace back to County Kildare on his father’s side. His great-great-great-grandfather left Mount Prospect in 1853 to escape the Great Famine.

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Walt Disney (1901-1966) - The early 20th-century entrepreneur’s father was born in the Province of Canada to Irish parents with origins in County Kilkenny.

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F. Scott Fitzgerald (1896-1940) -

One of America’s greatest modern writers was of Irish descent of both sides, though he didn’t identify as Irish-American. Times were different in the early 20th century, and Fitzgerald most likely rejected his ancestry because it set him apart from the elite he wished to be a part of.

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