Nate begins freshman year at Columbia, resides in the dorms, and plays lacrosse; however he's rarely seen there. In "It's a Dad, Dad, Dad, Dad World," Blair visits the campus to see Nate play a lacrosse game. While there, she sees two girls she met at Eleanor's fashion show (The Empire Strikes Jack). They ask if she's transferring to Columbia, and Blair lies and says yes. She loves Columbia, due to it being an Ivy, and because unlike NYU, everyone there reads Gossip Girl and knows who she is. Nate eventually catches on to her pretending to be a student, and advises her to stop. Jessica Leitenberg overhears and tips off Gossip Girl. At a benefit that evening held at Columbia, Blair confesses to a stranger that it's hard being there because she goes to NYU and hates it. When she formally introduces herself, he recognizes her name and says he works in the admissions office at Columbia. He explains he reviewed her application that day and tells her that she's been accepted for the next year. Confused and excited, she tells Nate what happened. Nate realizes that Chuck must have done it, as he had joked before about applying for Blair because she had too much pride. Later, she runs into the two girls from earlier and tells them that she will in fact be attending Columbia in the fall.
Blair finds out in "Belles de Jour" that Serena will also be attending Columbia. She's originally mad but eventually comes around to the idea. They begin class in "The Undergraduates," and attempt to be accepted at Hamilton House. However, Nate's new girlfriend Juliet Sharp is key master. This causes the house to accept Blair and not Serena. Later, Blair and Serena trick Juliet into causing a scene and it's revealed that half the board members of Bass Industries are in the house as alumni and Juliet keeping Serena out goes against code. This leads to Juliet being kicked out of the house.
In "Goodbye, Columbia," Serena admits to Blair that she keeps being late to class so it's making her look bad. Blair is trying to become guest lecture Martha Chamberlain's assistant, but fails due to her horrible attendance. Juliet uses Vanessa to steal Serena's phone. She stages an email where Serena offers on of her professors sex in exchange for grades. When the dean finds out, Serena desperately tries to explain that her phone was stolen, which saves her from getting kicked out.
Serena begins a short relationship with Colin Forrester, a professor at Columbia. But due to his being a teacher, they're forced to keep things on the down low.
In "War at the Roses," Juliet hides a camera in Colin's office to catch him and Serena together. After talking with Dan about things, she decides to end things with Colin. As a result, Colin quits his job at the school to be with her in "Juliet Doesn't Live Here Anymore." That night at the ballet, Juliet and Vanessa try to inform the dean about Serena sleeping with Colin, and try to give her a USB drive with the pictures. Before they do, Blair drowns it in a glass of champagne. Failing once again to get Serena in trouble, Juliet is driven out by Serena, Blair, Nate, and Chuck.
In "The Witches of Bushwick," the dean encourages Serena and Lily that due to a story about Serena being with Colin, the best choice for all is if Serena leaves. Lily informs the dean that out of all the Ivy's Serena was accepted at, she chose Columbia and threatens to get the press against the school. Later at Chuck's masquerade ball, Juliet drugs Serena and while she's passed out, Juliet emails the dean from Serena's email informing her that she wishes to withdraw from the school. After recovering, Serena calls the dean who grudgingly agrees to reinstate her.
In "The Kids Are Not Alright," Blair tries to intern with Indra Nooyi to fulfill her internship requirement for school and to further her own career.
- William van der Woodsen (attended med school there)
- Indra Nooyi
- Nate Archibald
- Blair Waldorf
- Serena van der Woodsen
- Juliet Sharp (former)
- Penelope Shafai
- Jessica Leitenberg
- Dean Reuther
- Colin Forrester (Former guest professor)