It is often said that everyone is Irish on St. Patrick’s Day. That is because St. Patrick’s Day has become a global celebration that is enjoyed by those of Irish descent as well as anyone who enjoys a good party.

Although you don’t have to be Irish to raise a pint or dig into some corned beef this March, there are plenty of people who can trace their lineage to the Emerald Isle, including some notable celebrities. Ahead of St. Patrick’s Day, check out these individuals that you might not have known have some Irish roots, courtesy of Irish Star, Hollywood Ancestry, Carrolls Irish Gift Shop, and Business Insider.

Nicole Kidman: Though Kidman grew up in Australia, the Oscar-winning actress has Irish and Scottish ancestry. Her father’s ancestors traveled to Australia as free settlers in 1839.

Marilyn Monroe: This popular 1950s film star adopted her mother’s maiden name “Monroe” when she began her acting career. Monroe’s maternal grandparents were American Midwesterners of Irish descent. It is said Monroe stems from the Gaelic Munro clan.

Robert De Niro: Despite having an Italian surname and having starred in many films in which he’s played an Italian character, De Niro has said he’s more Irish than Italian in regard to his heritage. His mother’s parents were both Irish and his father’s mother was Irish.

Christina Aguilera: Although this pop star’s Latin roots get most of the attention, Aguilera’s mother is Irish American.

Barack Obama: In 2007, Barack Obama was a presidential-hopeful and found out his great-great-grandfather Flamouth Kearney traveled from Ireland to America by way of Liverpool in 1850, giving the former president some Irish heritage.

George Clooney: With a last name like Clooney, it makes sense that the Academy Award winner has some Irish heritage in his background. His paternal great-great-grandparents Nicholas Clooney and Bridget Byron came to the United States from Ireland.

Anne Hathaway: The actress has said she has Irish ancestry through both parents and is believed to be more than 60 percent Irish. Her roots lie in counties Cork and Donegal.

Mariah Carey: This diva songstress has Irish ancestors on her mother’s side. Hollywood Ancestry traces that Irish heritage to at least her third great-grandfather, John Blanchfield, who was born in Ireland around 1822.

Meryl Streep: This award-winning actress has great-great-grandparents who were from Nunfanaghy on the north coast of County Donegal. They emigrated to Pennsylvania sometime between 1864 and 1870.

Many celebrities can trace their ancestry back to Ireland, giving them added incentive to celebrate this St. Patrick’s Day.