"The only one who knew it all, it just had to be you!"
-Blair to Dan, The Age of Dissonance
Novel Series Edit
Television Series Edit
Blair and Dan start out as enemies in the first season. They meet in The Wild Brunch, after Jenny Humphrey reveals Dan is her brother and that he went out with Serena van der Woodsen the night before. Blair tells Dan that Serena slept with Nate Archibald, then ran away and lied about it. After this, their only interactions are usually when Serena is involved. In Bad News Blair, they get on slightly better terms after Dan talks to Blair after she is humiliated by her mother and Serena. Blair and Dan work together in Much 'I Do' About Nothing, in order to take down Georgina Sparks, who has returned and started blackmailing Serena.
In the second season, they still stick to interacting only when Serena is involved. However, Dan begins to dislike Blair more when he learns she started the rumor he was sleeping with Rachel Carr in Carrnal Knowledge. When Blair is rejected from Yale due to an anonymous tip that she hazed a teacher, she blames Dan for tipping them off in The Age of Dissonance, but he later tells her it was Rachel. In Pret-a-Poor-J, Serena brings Blair to Dan to talk her into telling Chuck Bass how she really feels about him. He convinces her to take a chance and do it, until Vanessa Abrams admits to him that Blair and Chuck recently used her as a pawn in one of their games. Angry, Dan instills doubt in Blair, who then humiliates herself in front of Chuck.
Dan and Blair begin attending NYU and start becoming friendlier. Still wanting to be queen but feeling she's losing to Georgina, she asks Dan to take her to Georgina's rooftop party. He does, but Blair embarrasses Georgina and invites everyone to go to a bar with her. Over Blair's games, Dan announces it was a set up to get Blair more popularity and tells everyone to stay and party with him, which they do, in The Freshmen. In The Last Days of Disco Stick, Blair stars in a musical production written by Dan for the Tisch kids. However, she has to play referee between Vanessa and Olivia Burke, after they start behaving jealously toward each other after a threesome with Dan. Blair and Dan again team up in Ex-Husbands and Wives to save Rufus Humphrey and Lily van der Woodsen's marriage after William van der Woodsen arrives in town to ruin it.
After Serena is drugged, Blair and Dan work together to find Juliet Sharp and take her down, as well as find out what her motives are for destroying Serena's life. They ask Gossip Girl, who provides them with an address in Connecticut. They go together, and find Damien Dalgaard, who accompanies them on their mission for the rest of the day in The Townie. During Winter Break, Serena, Nate, and Chuck are all busy, leaving Dan and Blair the only ones still in town. They find they have similar interests in movies and museums, and begin to secretly hang out. In The Kids Are Not Alright, Dan calls Blair a dictator of taste when it comes to fashion, which makes her realize that maybe her future lies in working for a fashion magazine. Blair gets an internship at W Magazine in Damien Darko, but is taken aback when Dan also secures one there. They begin to compete, and eventually make a bet that whoever can bring the best author to the W Party that night can stay at the magazine while the other resigns. Blair calls her author, and Dan calls his, and both can attend. While at work, Blair is given the chance to sabotage Dan but chooses not to. She realizes this is the wrong choice after she discovers he sabotaged her. The two get into a physical brawl and both are fired. While packing up their desks, Blair admits that she worked hard to get an internship while Dan only had Lily make some calls. After finding this out, Dan resigns so Blair can keep her job. On Valentine's Day in It-Girl Happened One Night, Dan and Blair watch Rosemary's Baby together while on the phone. After Blair quits W Magazine in While You Weren't Sleeping due to it being too stressful, she goes to see Dan at the loft and they order pizza and watch a movie together. In Empire of the Son, Dan and Blair plan to reveal to everyone that they've started hanging out. However, their news is overshadowed by Lily turning herself into the police after forging Serena's signature. Rufus and Dorotea Kishlovsky both think that maybe a budding romance is what's going on, though they both deny it. At the end of the episode, they share a kiss to see if there really are any feelings between them.
In The Kids Stay in the Picture, Dan confesses to Eric van der Woodsen that he might have a crush on Blair. Chuck, having heard Blair had a life changing kiss, eventually finds out it was Dan. He sets him up so Blair can see Dan will never be a part of their world, but Blair tells him that she already knew that, and the kiss was only life changing because it made her see that her future lay with Chuck. She says the kiss meant less than nothing to her, and Dan agrees to save face. Vanessa overhears and leaves Serena a voicemail telling her. However, Serena doesn't believe her. But just to make sure, she makes her newly arrived cousin Charlie Rhodes (Ivy Dickens), follow Blair on a secret date just to make sure in Petty in Pink. She sees Dan and Blair together, and tells Serena. But when Serena arrives, she sees it's actually Louis Grimaldi and tells Charlie she was probably just confused on who Dan was. Louis is there secretly, and when his family finds out and orders him to come back to Monaco, Blair devises a plan to keep him there. She acts like she's really in a relationship with Dan and Louis has just come to attend the Pink Party. At the party, she kisses Dan and has the picture posted on Gossip Girl. A jealous Serena realizes Vanessa was telling the truth and informs Blair that the only interest she has in Dan stems from the fact that Serena had him first. Blair, however, defends her friendship with Dan, and that she considers them intellectual equals and they have a friendship on a different level than either have with Serena.
In The Wrong Goodbye, a newly engaged Blair leaves to spend the summer in Monaco with Louis. Before she goes, she tells Dan that she copied his Netflix queue and their movie discourse begins the following Monday. Eric notices the chemistry brewing between them, but says nothing.
In the fifth season, Blair has forgotten any romantic feelings she may have had for Dan, due to her upcoming wedding to Louis and her unresolved feelings for Chuck. However, Dan still very much has a crush on Blair. In Yes, Then Zero, Blair goes to Dan when she's thinking about leaving Louis but becomes angry when she realizes not only was Dan going to let her leave everything with no questions, but he knew Louis was protecting her. In Beauty and the Feast, Dan is the first person tells about her pregnancy voluntarily. She goes to see him that night, and admits she isn't sure if Louis or Chuck is the father, and Dan promises to be there for her no matter what happens. Eventually with the coaxing of Dan and Dorota, Blair decides to take a DNA test to figure out who the father is in The Jewel of Denial. But once she receives the results, she decides not to look. After Dorota finds out, she calls Dan, who tries everything to make Blair look. Eventually he physically puts them in her hand and encourages her to look, if not for herself, for the baby, and she does. After Dan's book Inside comes out in Memoirs of an Invisible Dan, Louis reads the parts with Blair and sees that Dan wrote about having sex with her. Upset, he cancels dinner with Blair and their parents and lies that his mother was delayed. Blair realizes it was Dan's book, and she too discovers what he wrote. She confronts him at his book release party, saying that what he wrote could end her engagement. He apologizes, and she makes up with Louis later. In All the Pretty Sources, Blair decides not to invite Dan or Chuck to her wedding shower. Upset at being left out, Dan gets drunk and shows up anyway, ready to reveal his true feelings to Blair. Chuck goes to get him and stop him from ruining Blair's night, but she becomes angry that he crashed the event. Afterwards, Serena explains to Blair that Chuck was doing her a favor by stopping Dan from ruining the party.