Charles Bartholomew Bass, or simply known as Chuck Bass, is a main character in the best-selling Gossip Girl series of novels, and is portrayed by Ed Westwick in the television series of the same name.

Born Charles Bartholomew Bass, he was raised in Manhattan's most elite social circles. He is the son of the wealthy Bartholomew Bass and his wife Misty and has a sibling named Donald. Bass and his family reside at the Plaza Hotel on the Upper East Side. Chuck Bass is a student at Riverside Preparatory School for Boys on the Upper West Side with scholarship student Dan Humphrey. He is shown as being the playboy of the series, interested in sex, money, and nothing more. He's virtually friendless, but accepted by the others since his parents are in the "in" crowd. He wears a monogrammed scarf and owns a pet monkey named Sweetie. In the final book, Greg and Dan Humphrey date briefly. Dan thinks Greg isn't right for him, and goes to tell him, except Greg beats him to the punch, leaving Dan for Chuck. At the end of the series, Chuck winds up being sent to military school because he didn't get accepted into any other colleges he applied to.

Chuck Bass was born to Bart Bass, a self-made billionaire who owns the New York Palace Hotel, where the two reside. Bass attends St. Jude's School for boys with best friend Nate Archibald, and enemy Dan Humphrey. Like in the book series, he is very interested in sex and money, though has more of a heart in the TV series.

Chuck grew up with Upper East Side elite Nate Archibald, Blair Waldorf, and Serena van der Woodsen. His father is Bart Bass, an entrepreneur, a successful businessman, who made a name for himself, rather than being born into money like Chuck's friends' parents. Chuck, unlike his father, was born into money, and therefore can be expected to take things for granted, like most of his peers do. Chuck is often described as the bad boy of his circle, and although he can be manipulative, we learn that he has a sensitive and caring side to him, especially for those he cares about like his best friend Nate and Nate's girlfriend Blair Waldorf. Chuck tends to be the playboy, and even tried to hit on Serena, but his lust for her quickly fizzled out. He also tried to sleep with Jenny Humphrey, but was quickly stopped by her brother Dan Humphrey, who happens to be Serena's boyfriend. Chuck was the only one who knew about Serena and Nate's affair, but didn't tell anyone until after Serena came back, at the brunch his father was hosting. Chuck is shown as being fiercely loyal to his best friend, Nate Archibald. When Nate leaves Chuck's party angry and frustrated, Chuck winds up rescuing him from Carter Baizen and a risky poker game. He has also said that the only things that matter to him are money, the pleasures money can buy him, and Nate. Although this can be contested, he clearly cares for Blair Waldorf, his close friend and love interest. Chuck's relationship with Blair continues into the debutante but the two try to keep things out of the public eye, mostly because Chuck doesn't want to hurt Nate. But Blair and Chuck have a fight and Blair ends up sleeping with Nate at the end of the debutante, which Chuck sees, causing him to leave NYC to avoid the pain it causes. Upon his return to NYC, he holds his secret relationship with Blair over Blair's head by threatening that if she is intimate with Nate at all, he will tell Nate about their relationship. This grows old with Blair and she dares him to tell Nate, because she believes that Nate will never believe Chuck over her; this conversation is caught on tape by Vanessa Abrams. In an effort to get back into Blair's good graces, Chuck buys what he thinks is the tape off Vanessa. In actuality, he bought a blank tape while Vanessa gave the real one to Blair free of charge. Seeing that his plan has failed to bring Blair back to him, he writes an anonymous text to Gossip Girl detailing that Blair has slept with someone other than Nate. The news spreads quickly and ruins Blair, and comes back to haunt him. After seeing the Gossip Girl news about Blair, Nate asks Jenny if it is true, and Jenny tells him that Chuck slept with Blair. As a result, Nate and Chuck have a explosive fight outside the school and Nate ends their friendship. At the end of the day, with no one to turn to, Blair returns to Chuck, but he rejects her, trying to remain loyal to Nate, saying that she is used goods and not worth his time. In the mean time, Chuck's father and Serena's mother have become engaged, causing them to become stepsiblings.