Chuck grew up on the Upper East Side with his three best friends and fellow elites Nate Archibald, Blair Waldorf, and future-stepsister Serena van der Woodsen. His father is Bart Bass, a self-made billionaire, which is irregular, compared to the Bass’ old money friends. Chuck is often described as the “bad boy of his circle”. Chuck is a playboy who sees women as recreational tools. Chuck frequently skips class and smokes marijuana. In the first episode of season one, Chuck attempts to sedue both Serena and Jenny Humphrey. His depiction as a sexual predator was abandoned in subsequent episodes, where his flaws were watered down to being a womanizer and manipulating those around him. In episode seven, “Victor/Victoria”, Chuck purchases a burlesque club, Victoria. After Nate and Blair break up, Blair visits Chuck at Victrola where she ends up performing on stage, and she later loses her virginity to him in the back of his limousine. Though she tries to deny the encounter, Chuck buys a necklace for her and admits that he feels “butterflies” in her presence, leading to a clandestine sexual relationship. Despite this, Nate and Blair rekindle their relationship, leading to a jealous Chuck revealing to the anonymous “Gossip Girl” that Blair and Chuck had a sexual relationship. This leads Chuck to have a temporary rift with both Blair and Nate. As Bart Bass and Lily van der Woodsen’s relationship progresses, they decide to move their families in together. Chuck and Eric van der Woodsen, Lily’s son and Serena’s younger brother, become especially close. When Serena begins receiving mysterious packages (pornography in the mail, alcohol delivered to her at school), she automatically blames Chuck. Bart subsequently forces Chuck to move out of the family home. Serena discovers that the culprit was actually Georgina Sparks, a past classmate of both Serena and Chuck. We later discover that Chuck lost his virginity to Georgina in the sixth grade. Chuck and Blair join together to prevent Georgina from further harming and embarrassing Serena. This process rekindles their bond, and they succeed in getting rid of Georgina. At Bart and Lily’s wedding at the end of Season 1, Chuck apologizes and confesses to Nate that he was in love with Blair. During the wedding reception, Chuck gives a speech about forgiveness that is implied to be directed towards Blair. She accepts his apology and the two kiss. However, as they are about to embark on a trip to Tuscany together, Chuck gets cold feet. Blair leaves for Tuscany without him.

In the season premiere, “Summer Kind of Wonderful”, we learn Blair has stayed in Europe. Chuck regretted his actions but told this to Blair too late as she was already dating Lord Marcus Beaton. Blair asks Chuck to tell her he loves her, but his fear of commitment stops him. In order to gather material for a story, Dan tags along with Chuck for a night, ending with the two of them in jail after a fistfight. While in jail, Chuck tells Dan in confidence that Chuck’s mother died while giving birth to him, and that his father blames him for her death, which explains their icy relationship. When Chuck later discovers that Dan was using him for a story, he feels betrayed and tells Dan that he was lying about all of it. Chuck’s storyline throughout season 2 mainly deals with his inability to tell Blair that he loves her. Eventually, his father is killed in a car accident. Lily adopts him so that he’s able to own Bass Industries, making Serena and Eric his sister and brother. When Blair begins dating Nate again, Chuck realizes his true feelings for her. The two team up to take down Poppy Lifton, and Blair realizes that she still has feelings for Chuck as well. She breaks up with Nate. In the final episode of season 2, Chuck admits to Blair his true feelings and the two finally begin a relationship.

When Season 3 returns, Chuck and Blair are very happy and very much in love. Chuck struggles to run Bass Industries to his deceased father’s impeccably high standards. He opens up a hotel, The Empire. Halfway through the season, Chuck meets a woman claiming to be his mother. Hit with a sexual harassment suit at work, he temporarily signs over The Empire. She betrays him and signs the hotel over to his sinister uncle, Jack Bass, who has previously attacked Lily and slept with Blair. Chuck and Blair agree to team up to take down Jack, but Chuck ends up offering Blair to Jack in exchange for his hotel. When Jack tells Blair this, she breaks up with Chuck at Dorota and Vanya’s wedding. Chuck tries desperately to win Blair back, doing everything from banning all of the other Upper East Side men from dating her to asking her to meet him on top of the Empire State Building. Blair decides that Chuck is her true love and she’s going to meet him, but Dorota suddenly goes into labor and she ends up being late. Chuck, thinking she is finally over him, leaves the building heartbroken and nearly suicidal. When he gets home, he sees that Jenny Humphrey has arrived looking for Nate. The two drunkenly sleep together, heartbroken that their true loves don’t return their feelings. Blair appears later in Chuck’s suite, apologizing for being late, and the two reunite. Chuck is about to propose to Blair at the hospital, as they visit Dorota and her new baby, when Dan appears and rashly delivers a punch to Chuck’s face. He then forces Chuck to tell Blair what happened between him and Jenny. Blair breaks things off with Chuck and informs him it’s for good. She also threatens to ruin Jenny’s life if she doesn’t leave Manhattan immediately for good. Chuck then travels to Prague to escape New York for a while, feeling as though he has nothing left. He gets robbed by three muggers who insist on taking the ring that Chuck intended on proposing to Blair with and when Chuck puts up a fight, he gets shot in the stomach. The last shot of season 3 is him lying in an alley, presumably dying.

In the first episode of season four, we find that Chuck is alive and well, having been rescued by Czech girl, Eva who has no idea of his wealth or of who he is. He creates a fake name and persona as he no longer wants to be the manipulating Chuck Bass. He eventually reveals who he really is and returns to New York with her, at the request of Blair and Serena. Blair insists she no longer loves him, but still schemes to undermine his new relationship. He eventually falls for one of her schemes and breaks up with Eva. He realizes his mistake and begs her to take him back, but she refuses, saying that he showed his true feelings by continuing to believe Blair over anyone else. Chuck then declares war on Blair, inviting Jenny Humphrey back to town, and generally trying to make her miserable. They soon blossom into an enemies-with-benefits relationship. In the “The Witches of Bushwick”, Chuck accidentally tells Blair that he loves her during sex and, not knowing whether his words are true, Blair chooses to gloss over the moment. Although Chuck and Blair spend the episode striving for different ends which will eventually alienate each other (Blair to become the face of Anne Archibald’s charity, Girls Inc, and Chuck to increase the revenue of The Empire by returning to his bad boy persona), Blair makes the decision to attend Chuck’s Saints and Sinners party in order to confront him. Chuck confesses that he loves her, and the pair kiss in front of everyone after the curtain concealing them is pulled down. Anne tells Blair that she can no longer be a part of Girls Inc just as Chuck’s publicist KC tells Chuck that she thinks Blair will be good for business. Blair re-thinks her decision to sacrifice it all for their relationship, and she and Chuck break up once again. Chuck promises he’ll wait for her, and both affirm their belief that their love will reunite them in the end. On thanksgiving Chuck and Blair run into each other at Serena’s house, Chuck offers to leave but She tells him that she was heading to JFK anyway and came to drop off the traditional pie and that they should get used to this. They hear about Serena being hospitalized and while they’re sharing that maybe nothing can change between them, Jenny walks in and their conversation interrupts. While driving Blair home, Chuck tells her that he showed up only for Serena. When she told him that what happened with Serena made her question what she told him after the Saints & Sinners party; Chuck tells her that he cannot be her friend now as much as he wishes he could. After that Blair still sends him her traditional pie, saying that even if they can’t be friends it doesn’t mean that they aren’t. In “The Townie” episode, It was revealed that Lily was going to sell Bass Industries instead of giving Chuck the company back. So he sets off to New Zealand, where his uncle Jack Bass is currently living. Chuck returns to the Upper East Side with revenge for Lily. Chuck’s new love interest Raina and her father, Russell Thorpe, a former rival of Chuck’s late father Bart Bass. Chuck, however, manages to save the company after it is reveled that Russell accidentally killed his wife in a building fire that Bart was originally accused of. Later, Blair is kidnapped by Russell, but Chuck saves her, and the two go to a Bar Mitzah. There, the two are seen dancing and smiling happily, disapproving the idea that Chuck cannot make Blair happy. The two have sex, and Blair decides she is going to leave Louis, but Chuck stops her, telling her that she needs to be with Louis because he makes her happy. At the end of the episode, Chuck decides to spend the summer traveling with Nate, and it also revealed that Blair may be pregnant with Chuck’s baby.

In the first episode of season 5, we find out that Chuck has spent his summer travelling the world with Nate. The two arrive in Los Angeles to meet up with Serena, who is working as an assistant on a film set. Seemingly over his break up with Blair, Chuck exhibits a positive outlook on life, telling Serena and Nate that he’s seeking to experience everything he can in life. However, his heartbreak soon becomes apparent when he receives an invitation to Blair’s upcoming wedding, which causes him to drive recklessly and get into a motorbike accident. In the following episode, it is revealed that Chuck has an emotional disorder as a result of his losing Blair, and which now causes him to be numb to physical and emotional stimuli. Dan Humphrey decides to help Chuck break through this emotional barrier, and gets him a dog, hoping to spark some emotion. However, it is only when Blair reveals to him that she is pregnant with Louis’s baby does Chuck begin feel again - he is shown crying at the end of the episode. He names the dog “Monkey.” He forms a reluctant friendship with Dan Humphrey from here on. He meets a psychiatrist, Eliza Barnes, who tells him that he acts out because he never had a childhood, and needs help. When he finds himself falling back into his old patterns, he calls Dr. Barnes, ready to seek help. However, it is revealed that Blair’s fiance, Louis, gives Dr. Barnes money to upset Chuck, in hopes that he will do something reckless and drive Blair away forever. When Chuck finds this out, he publicly exposes both Dr. Barnes and Louis, leaving Blair devastated. Later that same night, he goes to Blair’s apartment to apologize to her for all the times he’s hurt her and let her down. His apology recounts all the obstacles Chuck and Blair have faced in their relationship thus far, and prompts an emotional Blair to thank him. Chuck assures her that she is going to be “an amazing mother”, having come to terms with her relationship with Louis. He resolves to keep his distance from her after that, but is seduced by her in “The Big Sleep No More”, when a conflicted Blair seduces him in hopes to prove that his efforts to be a better man is just a ploy to win her back. When he kisses her, she slaps him, and tells him that he will never change. It is later revealed that he conspired with Dorota and kissed Blair in order to confirm her suspicions of him, and push her back to Louis. In the same episode, Serena states that Chuck has been seeing a therapist regularly. In the following episode, Blair figures out that Chuck tricked her when she goes to his apartment and witnesses him helping Dan. She says: “You’ve really been good this whole time, haven’t you?” In the episode ‘Riding in Town Cars with the Boys’ he is seen admitting to Blair that he still loves her and that they still have a strong chance at being together despite the fact that she is carrying another man’s child. They profess their love for one another in Chuck’s limo and Chuck explains to Blair that he plans to love her child as though it is his own because he loves her too much to lose her. This occurs whilst the limo is being chased by three paparazzi on motorbikes and results in a car crash. Lilly reveals at the conclusion of the episode that Blair is awake and doing fine, but whether or not Chuck has survived is not revealed.