With an estimated 33 million Americans claiming Irish ancestry, it’s hardly a surprise to learn some of the biggest names in Hollywood claim to have Irish blood pumping through their veins.
Even so, some of the names that feature on this list might surprise you. Here are 29 Hollywood actors, actresses and figures with their own special links to Ireland.
29. Sean Penn
Penn is part Russian, Lithuanian, Italian and, most importantly, Irish.
28. Courteney Cox
The Friends star is distantly Irish, through her father's side of the family.
27. Stephen Colbert
Stephen Colbert is actually the youngest of eleven children in an Irish Catholic family.
26. Rosario Dawson
Dawson is part Afro-Cuban, Puerto Rican, Native American and Irish.
25. Harrison Ford
Indiana Jones is actually half Irish through his father Christopher's side of the family.
24. Alicia Keys
Keys boasts an impressive multiracial heritage – her mother Teresa is of Sicilian and Irish descent.
23. Kevin Bacon
The Footloose icon grew up as one of six kids in a close-knit Philadelphia family and is distantly Irish.
22. Lindsay Lohan
Lindsay is Irish through her father Michael Lohan, her former manager.
21. Chris Evans
Captain America's blood runs green, thanks to his Boston family's Irish-American roots.
20. Julia Roberts
Julia Roberts Hollywood's original Pretty Woman is Irish, English, Scottish and Welsh.
19. Robert Downey Jr.
Iron Man has Irish blood coursing through his veins from his father's side of the family.
18. Jennifer Connelly
Connelly's Roman Catholic father is of Irish and Norwegian descent.
17. Johnny Depp
Depp may reside in France and his ancestry may be predominantly English but there's also some Irish in there on his mother's side.
16. Olivia Wilde
Wilde is Irish through her father’s side of the family and spent many summers in Ardmore, County Waterford.
15. Elijah Wood
Frodo Baggins boasts English, Irish, German and Polish heritage.
14. Megan Fox
The Transformers star is of Irish, French and Native American descent.
13. Matthew McConaughey
He may seem like Mr Texas but his mother's family hail from the Cavan/Monaghan area while his dad also has Irish blood in his veins.
12. Gwen Stefani
There's No Doubt about Gwen's roots - she was born to an Italian father and an Irish/Scottish mother.
11. Tom Cruise
He struggled with the accent in Far And Away but Tom does come from a mix of German, English and Irish ancestry.
10. Christina Aguilera
Aguilera’s Latin roots are well documented, but she also boasts some Irish heritage through her mother.
9. George Clooney
Good news! The sexiest man alive is also half Irish!
8. Mariah Carey
Did you know Mariah Carey is half-Irish through her mother Patricia Hickey? You do now.
7. Tom Brady
An Irish Catholic City needs an Irish football hero and Brady is it – his dad is of Irish descent.
6. Katherine Heigl
The Knocked Up actor's father, Paul Heigl is of both German and Irish descent.
5. Alec Baldwin
Alec and the other Baldwin boys are a melting pot of Irish, English and French origins.
4. Anne Hathaway
Though her surname originates from England, both of Anne’s parents are of Irish ancestry.
3. Barack Obama
The 44th President of the United States has his mother, Ann Dunham, to thank for his Irish ancestry.
2. Kristen Bell
The voice behind Frozen’s Princess Anna is part Irish through her father, Tom.
1. Ben Affleck
Not only is Batman distantly related to fellow Bostonian Matt Damon, he’s also of Scottish, English and Irish descent.