0Look Who's Irish!Will Christina Aguilera, Emilio Estevez, and Barack O'Bama be celebrating St. Patrick's Day this year? See 16 stars with surprising Irish ancestry.Updated Jul. 14, 2017 12:15PM EDT / Published Mar. 15, 2010 12:33PM EDT Jennifer Graylock / AP Photo Robert De NiroJennifer Graylock / AP Photo Lindsay LohanJoel Ryan / AP Photo Emilio EstevezJorge Herrera Barack ObamaJ. Scott Applewhite / AP Photo Christina AguileraChris Pizzello / AP Photo Harrison FordJunko Kimura / Getty Images Alicia KeysDan Steinberg / AP Photo Ben StillerCharles Sykes / AP Photo Ana OrtizRetna John TravoltaJason Merritt / Getty Images John StamosWalter McBride / Retna Gwen StefaniCarlos Diaz / Retna Marlon BrandoAP Photo Janeane GarofaloGraham Jepson / Retna Henry Louis Gates Jr.PBS Kathy Ireland Gaas / AP Photo
Robert De NiroJennifer Graylock / AP Photo Lindsay LohanJoel Ryan / AP Photo Emilio EstevezJorge Herrera Barack ObamaJ. Scott Applewhite / AP Photo Christina AguileraChris Pizzello / AP Photo Harrison FordJunko Kimura / Getty Images Alicia KeysDan Steinberg / AP Photo Ben StillerCharles Sykes / AP Photo Ana OrtizRetna John TravoltaJason Merritt / Getty Images John StamosWalter McBride / Retna Gwen StefaniCarlos Diaz / Retna Marlon BrandoAP Photo Janeane GarofaloGraham Jepson / Retna Henry Louis Gates Jr.PBS Kathy Ireland Gaas / AP Photo