|Birthday||4 June, 1986|
|Birth Place||Madrid, Spain|
|Appearances||"A Scandal in Belgravia"|
She is the granddaughter of famed actor and director Charlie Chaplin, and named for her grandmother (his wife), who was born Oona O'Neill, daughter of playwright Eugene O'Neill. She previously portrayed Marnie Madden in BBC's The Hour and Talisa Maegyr in HBO's Game of Thrones.