Ellie Langford is a principal character in the Dead Space series. She is a Class 4 Heavy Equipment Pilot for the Concordance Extraction Corporation and one of the very few survivors of a Necromorph attack aboard the space station known as The Sprawl. Isaac Clarke first encounters Ellie fighting off Necromorphs in the market district of the station when she shoots in his direction and they eventually become good allies, with Ellie taking care of mentally disturbed survivor of the attack Nolan Stross, while Isaac searches through the space station trying to find the means for their escape.

Ellie's eye was replaced after its removal by Nolan Stross, but she still had her ambition to stop the Markers that have now spread to every major colony. Ellie leaves due to Isaac's refusal, leaving her on her own to stop the Markers. While on the planet Uxor, she develops a relationship with Captain Robert Norton. The two, along with Sgt. John Carver, witness the Necromorph infestation of the planet. Ellie eventually traces the source of the Marker's signal and power to Tau Volantis, which she believes is the Marker home world, and sends Norton to recruit Isaac for the mission. During the events of the game, Ellie attempts to stop the tension between Norton and Isaac involving their relationship with her and while trying to stop the Markers.