Who was the pregnant survivor on Oceanic Flight 815?

Claire Littleton was the pregnant survivor on Oceanic Flight 815. Played by Australian actor Emilie de Ravin, Claire is introduced in Lost's pilot episode as a young woman traveling from Sydney while nearing the birth of her first child.

Claire's pregnancy quickly becomes central to the survivors' story. After the crash, she worries about her unborn baby and receives medical help from Jack Shephard. She later gives birth on the island to Aaron Littleton, with Charlie Pace helping her through the delivery. Claire's baby is not simply a background detail: several characters believe Aaron has unusual importance, and his safety becomes one of the show's recurring concerns.

Viewers sometimes confuse Claire with Sun Kwon, who also has an important pregnancy storyline, or with Shannon Rutherford and Kate Austen, who are other prominent female survivors. Claire's history also connects her to Jack in an unexpected way: Christian Shephard, Jack's father, is revealed to be Claire's biological father, making Claire and Jack half-siblings.