At the beginning of the series, Ellie is throwing a birthday party for Chuck and has invited a number of her girlfriends for him to meet in hopes of helping him get past Jill.

"[7] Most of Ellie's appearances in the series have been as part of the side-plots involving Chuck's real life and coworkers at the Buy More, so she has rarely figured prominently into the main arc.

Her most significant role in the main plot of an episode came in "Chuck Versus the Truth," in which Ellie attempted to treat nuclear expert Mason Whitney when he was poisoned by Reardon Payne.

For her sake, Chuck convinced Devon not to go through with a plan to overwhelm Ned, and later identified himself as the Intersect to Mauser to prevent him from killing her.

[3] Morgan also offers her support and comfort during a fight with Devon, where he admits he sees her as a sister (that he wants to have sex with so bad).

Devon is initially opposed to the idea because he wants to get himself and Ellie away from the danger attendant with Chuck's spy life, but he relents, realizing how important the opportunity is to her.

Soon she is granted a sabbatical, allowing her to take a year off so she can both pursue the fellowship and go to Africa with Doctors Without Borders as Devon planned.

[15] In "Chuck Versus the Tooth" Ellie is manipulated by a Ring operative she met in Africa named Justin into believing that Casey is a double-agent and a threat to her father.

She openly admitted being impressed with Chuck's skills when he and Sarah helped both Ellie and Devon, and Generalissimo Goya, escape a coup d'etat in Costa Gravas.

The story Mary told her about road trips in the family's old Mustang led her to the realization that a car she had seen in the classifieds of the newspaper—which she was searching due to her father's habit of leaving her coded messages in such a manner—was indeed left behind by Stephen as she suspected.

In the episode "Chuck Versus the Muuurder", Ellie devotes her time to the research on the laptop, after it is given to her by National Clandestine Service Director Jane Bentley.

Sarah Lancaster was cast in the role of Ellie Bartowski in March, 2007,[16] joining Zachary Levi, Adam Baldwin and Yvonne Strahovski.

On January 16, 2009 it was announced that Scott Bakula would be appearing as Chuck and Ellie's father Stephen in a three-episode story.

[17] Ironically, considering that Chuck's secret life has led him to save Ellie's on three occasions, she still plays the role of the over-protective older sister and deep-down still sees him as her baby brother.

[20] She loves him dearly, but under the effects of truth serum angrily complained about his frequent use of the word "awesome," and what she felt as moments of neglect of her feelings in the relationship.

[4] Ellie later accuses him of self-centeredness and disregard what she wanted when he bought a washer and dryer for their anniversary (as opposed to a big-screen TV).

In "Chuck Versus the Gravitron," Devon's parents are supposed to come over for Thanksgiving and Ellie's nervousness manifests with her cleaning at a hurried pace, cooking multiple turkeys (which she promptly throws in the trash for flaws only she notices) and uninviting Morgan.

[21] She was hurt, and believes Chuck and Morgan are covering up willful actions taken by Devon during the party (she later learned the truth).

And like Chuck, Ellie also has a trusting nature, which the Ring used to manipulate her into thinking that her handler was CIA and that Casey was a double agent.