Ellie is a fictional character in the 2013 video game The Last of Us, and the protagonist of the upcoming video game The Last of Us Part II. In the first game, the character Joel is tasked with escorting Ellie across a post-apocalyptic United States in an attempt to create a potential cure for an infection to which Ellie is immune.

She is voiced by Ashley Johnson, who also provided motion capture for the character. While players briefly assume control of Ellie for a portion of the game, the computer's artificial intelligence primarily controls her actions, often assisting in combat by attacking or identifying enemies. Ellie reappeared as the sole playable character in the downloadable content prequel campaign, The Last of Us: Left Behind, in which she spends time with her friend Riley.

Ellie is also the main character in the comic book prequel, The Last of Us: American Dreams, wherein she befriends Riley and has her first encounter with the rebel group the Fireflies. Ellie was created by Neil Druckmann, the creative director and writer of The Last of Us. Inspired by a mute character proposed for Uncharted 2: Among Thieves, Druckmann created her as a strong female character with a close relationship with Joel; throughout the game's development, the relationship between Ellie and Joel was the central focus, with all other elements developed around it.

Johnson inspired aspects of Ellie's personality, prompting Druckmann to make her more active in fighting hostile enemies. Naughty Dog also redesigned her appearance during the game's development to more closely resemble Johnson. The character has been well-received by critics, with Ellie's relationship with Joel most frequently the subject of praise.

The strength and complexity of her character, and its subversion of the damsel in distress stereotype, have also been commended. Ellie's role in Left Behind's plot has prompted some social commentary within the industry, with coverage focusing on a scene depicting LGBT themes. Both the character and Johnson's performance received numerous awards and nominations, and have regularly been placed favorably in polls and lists. Ellie's mother was forced to give her up shortly after she was born, and she was initially raised by Marlene, who was a friend of Ellie's mother.

She later attends a military boarding school in the Boston quarantine zone, where she befriends Riley Abel, a fellow rebel who protects her from bullies, as depicted in the comic book series The Last of Us: American Dreams. During the events of Left Behind, which take place several weeks before the beginning of The Last of Us, Riley returns to Ellie after a long absence and tells her that she has joined the Fireflies, a revolutionary militia group.

While spending time together at an abandoned shopping mall near the quarantine zone, Riley reveals that she is about to be posted to another city, and Ellie hesitantly supports her decisions. Riley abandons her Firefly pendant when Ellie pleads for her to remain. In response, she impulsively kisses Riley who happily responds. Drawn by the noise of their activities, the Infected pursue Ellie and Riley. They attempt to escape, but are bitten.

The pair considers suicide, but chooses to spend their final hours together. However, Ellie survives the infection and seeks help from Marlene, the leader of the Fireflies. She agrees to escort Ellie as she tries to find a cure thanks to her immunity to the Infected. Marlene is later wounded, and early in The Last of Us, assigns Joel the task of escorting Ellie. Initially annoyed by Joel's surliness, Ellie begins to feel a strong attachment to him.

However, upon learning that he intends to leave her with his brother Tommy and return to Boston, she runs away. She later confronts him demanding that he not abandon her. This strengthens the bond between them, and they continue their journey. After experiencing a traumatizing encounter in the Winter, where Ellie is nearly raped and murdered by a band of cannibals and their leader David, she becomes withdrawn and introverted.

When Joel finally gets her to the Fireflies, it is discovered that Ellie requires an operation to remove the mutant strain of the Cordyceps fungus growing on her brain, which may be used to create a vaccine; the operation will likely kill her. While she is being prepared for surgery, Joel kills Marlene and the Fireflies, makes his way to the operating room, and carries Ellie to safety.

Because she was unconscious during the battle, Ellie is unaware of what has transpired. As they leave the hospital, Joel lies about the events, telling her that the Fireflies had found many other subjects, and had stopped looking for a cure. When Ellie later confronts him about it, describing her survivor's guilt and demanding to know the truth, Joel reassures her that he is telling the truth; she replies "Okay".