Olivia is introduced in Dan de Fleurette where she pays for Dan's cup of coffee after he forgets his wallet. She introduces herself as Kate, not wanting to reveal her identity as a famous actress, as Dan has no idea who she is. She becomes Vanessa's roommate at NYU, and Vanessa is a big fan of The Endless Knights movie series that Olivia is famous for. Later, Dan notices Olivia at a cafe while he is there with Nate, who also knows who she is. He encourages him to ask her out, which he does. Olivia cancels on a late night talk show appearance to go out with him. The next day, he admits to Olivia that after his last few relationships, he feels she's refreshingly cool and normal. Olivia tells him that if he's looking for something normal, she might not be the girl for him as much as she wishes she was. Soon after, Vanessa and Dan plan to attend the movie premiere Fleur, which stars Olivia. Once there, Dan realizes who she is but decides he likes her anyway and the two enter into a relationship.
After doing press in Japan, Olivia returns to NYU in Enough About Eve. She brings Dan and Vanessa gifts back from her travels, and Dan invites her to attend the Parent's Night Dinner at school and meet Rufus and Lily. She's excited, as she has never met any of her boyfriend's parents. However, Vanessa is vying for the chance to give the Freshman Toast at the dinner and when she finds out Olivia is not only coming, but giving the toast, she pits Dan and Olivia against each other to secure it. She tells Dan that Olivia is stressing over meeting his parents, and Olivia that Dan thinks it's too soon and Rufus and Lily look down on shallow Hollywood celebrities. Dan and an offended Olivia end up attending the dinner and Olivia acts as if she's a shallow celebrity, calling her astrologer and talking loudly and obnoxiously. After she and Dan realize Vanessa's plot, she apologizes to Rufus and Lily, who overlook it.
In How to Succeed in Bassness, Dan, curious about Olivia's movies, decides to watch them with Nate, who tells them that the rumor is that while they were filming, they started hooking up for real. While watching, he observes a sex scene between Olivia and her costar Patrick Roberts. Olivia calls while he's watching them and he pretends he has the flu, but she comes over later and reassures him that Patrick was never her boyfriend and it was all acting. To help Serena, who is undergoing pressure from her new boss, Olivia's publicist KC to break them up, Olivia agrees to attend Chuck's club opening with Patrick as her date. However after the party is raided by the police, Olivia confesses to Dan that she lied earlier and Patrick was really her boyfriend at one point, and their breakup broke his heart. But she tells him also that he is the only one she wants to kiss, and she does, while Serena opens the curtains and reveals their relationship to the paparazzi. Afterwards, they have sex for the first time.
After appearing on an interview with Jimmy Fallon in The Grandfather: Part II, Olivia realizes she said something she will regret. During her interview, she told a story about how on her first date with Dan, he came back from the bathroom at one point with his shirt inside out, supposedly because a spider crawled inside. Jimmy dubbed him "Bathroom Boy", and it's not long before others begin to refer to Dan as that too. Olivia desperately tries to keep him away from it, but he eventually watches it and leaves in the middle of a board game at the VDW's. Olivia goes after him, but when she gets to the loft, Dan reveals he had forgotten about their anniversary until he saw her mention it on the show. After they celebrate, they watch the end of the Jimmy Fallon episode where he makes a cake to apologize to Dan for calling him out.
Olivia receives word in They Shoot Humphreys, Don't They?, that the next Endless Knights chapter is happening and she needs to leave school to start shooting. Sad at this news, Dan and Vanessa devise a plan to keep her there, including finishing a bucket list of everything each college kid needs to do at least once. They finish almost everything on the list, which included attending a club called Fat Black Pussy Cat, throwing a party, and playing in fountains. Olivia asks why they didn't finish the list until she finds out it's having a threesome. Not wanting to leave without finishing it all, they three engage in a threesome. After it's over, Olivia receives a text saying the movie is off.
Olivia makes her last appearance in The Last Days of Disco Stick. She engages in jealous behavior towards Vanessa over Dan as a result of their threesome. Olivia gets Dan into a cabaret program with the Tisch kids, and he picks Vanessa to direct while Olivia stars in it. Things get complicated real quick, and end when Blair figures out what happened and talks to both girls individually. During show time, Olivia misses her cue so Dan is forced to kiss Vanessa again and realize his feelings for her. After, she confesses to him that during their tryst, he looked at Vanessa like he never once looked at her. He denies it, but she replies that him even acknowledging it proves it happens. She announces she's taken another movie and leaving, but says she'll come back. She never does.