Dan joins Blair, Vanessa and Georgina at NYU and instantly fits in amongst many aspiring writers. His stay at NYU also tests his friendship with Vanessa, who assumes that Dan has been absent in their friendship ever since he became wealthy. Dan explains to Vanessa that he and his family are still adjusting to their nouveau-riche status and Vanessa leaves frustrated at Dan.
Dan's first ngày at NYU reveals Georgina Sparks' return. When Georgina throws a party, Blair's attempt at sabotage results in Dan standing up for Georgina. Dan is được ưa chuộng at NYU, and his influence leaves Blair ostracized.
Dan and Georgina's relationship is short-lived in the episode "The Mất tích Boy". Georgina sends Blair on a wild ngỗng chase to enter an elite secret society that gets her into a bidding war with Chuck âm bass, tiếng bass, bass at an auction. Serena recognizes Georgina's handwriting in Blair's invitation to the secret society and confronts her. The Humphrey family leaves and Georgina is left alone at the auction. Serena reveals Georgina's scheming to Dan and Dan ends his relationship with Georgina. Georgina leaves for Boston when she discovers that Scott, Vanessa's boyfriend, is Rufus and Lily's love-child and that Vanessa had known that he was for a long time.
In "Dan de Fleurette", Dan moves on from his relationship with Georgina when he meets Olivia, a movie ngôi sao who attended NYU to be a normal college student. Dan first meets Olivia, who calls herself Kate until her movie premiere of Fleur reveals that she is Olivia Burke, a Hollywood movie star. Olivia apologizes to Dan and they embark in a new relationship.
Georgina's return from Boston has her blackmailing Vanessa when she discovers that Dan has moved on from their relationship so quickly in "Rufus Getting Married". Dan, then persuades Vanessa to reveal her secret, only to find out that Scott Rosson is his half-brother, the love-child of Rufus and Lily. Rufus and Lily's wedding has Dan and Vanessa reluctant to tell the truth about Scott. On Rufus and Lily's wedding when Lily gets cold feet, Rufus confronts her with Scott unknowingly asking if their wedding was off. Lily scolds Scott and Georgina reveals that Scott is their love-child. Dan arrives with the rest of the family and confirms Georgina's statement. Dan and Blair find Georgina eating the wedding cake and Blair leaves. At the end of the episode, Dan expresses regret that Georgina left unscathed. Blair assures him that she didn't bởi sending Dorota and Vanya to get rid of her.
Dan and Olivia encounter several troubles in their relationship when Vanessa alienates them both during her attempt at getting the freshman bánh mì nướng at NYU. When Dan introduces Olivia to Rufus and Lily, she starts diễn xuất like a stereotypical movie ngôi sao towards them until Vanessa reveals that she lied to the both of them so that Olivia wouldn't have to meet her judgmental mother, Gabriela. Vanessa loses the bánh mì nướng to Olivia and properly reintroduces Olivia the tiếp theo morning after the incident. Olivia's movie ngôi sao background also catches up to her when she is forced to continue her fake relationship with Patrick Roberts, her former co-star. Serena intervenes and Dan and Olivia soon manage to make their relationship public.
Dan and Olivia's relationship soon comes to an end when Olivia is again forced back into the world of film and return to Hollywood but not without Dan and Vanessa giving her the best college experience. The college experience results in a threesome that consequently leads to Dan and Olivia's break-up when Olivia states that Dan has feelings for Vanessa. Vanessa unfortunately, falls for theater student, Paul Hoffman.
With Olivia gone, Dan confesses his tình yêu for Vanessa during the anniversary of Bart Bass' death but Vanessa turns him down. Dan attempts to impress Vanessa bởi impressing Gabriela that ends with Gabriela telling Dan that if he breaks Vanessa's heart, their friendship wouldn't make it. Vanessa eventually reveals her feelings for Dan at a bờ biển, bãi biển party when Dan arrives with a fresh ngày and Vanessa gets back together with Paul Hoffman. Dan had been unaware that Vanessa had ended her relationship with Paul until Paul and Dan's ngày reveals each others' predicaments, get together and leave Dan and Vanessa at the party. Dan and Vanessa reveal their feelings toward each other and Kiss at the end of the episode.
Dan finds little trouble with his relationship with Vanessa and reveals their relationship to Rufus. Vanessa, frustrated at the lack of something different in their relationship, heeds Nate's Lời khuyên on role-playing and sets up a ngày fashioned according to Dan's yêu thích movie Rear Window. Vanessa is not convinced that Dan appreciates what she did for her date, and she leaves. Dan confronts her and tells her that their relationship is different from their friendship.
Dan applies to get into Tisch's nghề viết văn program as Vanessa reads and secretly critiques one of the stories that he plans on submitting for admission. Dan secretly read Vanessa's film script and is impressed, unaware that Vanessa is also applying for the same program.
Towards the end of the season, Vanessa decides to accept an internship with CNN, that of which requires her to go on a six tháng trip to Haiti. Despite this, the two of them decide that they can still maintain their relationship as a long-distance one.
In the season finale, Dan wakes up with Serena in his bed. The viewers learn that the two did not sleep together but - after staying up until 4AM talking and drinking wine - they shared a kiss, that of which Serena classifies as them "falling into a comfortable path for one...or ten minutes". When Dan hears that Serena breaks up with Nate, he calls her, possibly to say he had feelings for her. When she announces she wont be back to talk to him till September he appears very disappointed. He then shuts the e-mail he had opened to write to Vanessa, his current girlfriend, who is no longer taking his calls (due to Nate's interception after finding out from Gossip Girl's blast and later overhearing at the hospital about the kiss). When he later learns that Serena is going to Paris with Blair, he goes online to book a ticket. Before he can, however, Georgina visits Dan and tells him that she's pregnant with his child. Season 4
It is revealed Georgina had a son, Milo, on July 7, 2010, but it is unknown if Dan is the father, because they never did a DNA test. It is later revealed to be another one of her schemes when she abruptly leaves New York, leaving Dan alone with Milo. She left a note saying that she went to the "spa". Georgina returns from the "spa" (she was in fact in St. Barts) to tell Dan about Serge, Milo's real father, and to say that she and Milo are going to live with Georgina's parents. Dan is sad to see Milo go. He tries to embark on a relationship with Serena, who is still torn over him and Nate. Blair and Dan team up to find Juliet in Connecticut. They do find her with Serena, but get a shock when Serena tells them that Lily was the one who put Ben in jail instead of herself.