Kurt Elizabeth Hummel is a fictional character from the Fox musical comedy-drama series Glee. Series creators Ryan Murphy, Brad Falchuk and Ian Brennan initially conceived of him as a fashionable gay countertenor who is routinely bullied at school. Kurt is portrayed by actor Chris Colfer, and has appeared as a character on the show since its pilot episode, first broadcast on May 19, 2009. Glee follows the trials of the New Directions glee club at the fictional William McKinley High School in the town of Lima, Ohio, of which Kurt is a member. His storylines in the first season focus on his struggle with his sexuality as he comes out to his father and friends, and deals with his romantic feelings for Finn Hudson, the straight co-captain of the glee club.

In the show's second season, Kurt is forced to transfer to a private school for his own safety after a closeted gay classmate bullies him relentlessly and then threatens to kill him. Kurt joins the Dalton Academy Warblers, the school's glee club, which is a competition rival of New Directions, and is befriended by their openly gay lead singer Blaine Anderson. Later on, the two become romantically involved. Their relationship has been well received by critics, and they have been named "one of the most beloved TV couples of the millennium" by Jarett Wieselman of the New York Post. Kurt eventually transfers back to McKinley and rejoins New Directions, but continues his relationship with Blaine, who transfers to McKinley in the third season. In the fourth season, Kurt moves to New York City with his best friend Rachel Berry, where he pursues his musical education while interning for Vogue.com. For the remainder of the series, Glee charts Kurt's life in Lima and New York as he grapples with young adulthood and realizing his career ambitions.

Colfer describes Kurt as projecting a very confident "I'm better than you" personality, despite being a typically scared and anxious teenager. Kurt's solos for New Directions tend to be songs—usually show tunes—traditionally performed by women, which best suit his countertenor voice. His occasionally complex—but always loving—relationship with his father has been a focus for the show. Colfer's portrayal of Kurt has received much critical praise, and he has been the recipient of several awards, including Best Supporting Actor in a Series, Miniseries or Television Film at the 2011 Golden Globe Awards. He has also garnered many award nominations, which include the 2010 and 2011 Emmy Awards for Outstanding Supporting Actor in a Comedy Series.

Prior to being cast in Glee, Colfer had no professional acting experience. He originally auditioned for the role of Artie Abrams, performing "Mr. Cellophane" from the musical Chicago. Murphy was so impressed by his performance that the role of Kurt was created for him. To keep the number of students in the glee club constant, a character named Rajish was cut from the show. Kurt's name is inspired by the character Kurt von Trapp from The Sound of Music, a role that Colfer once played as a child. The Hummel surname comes from the popular German Hummel figurines; Colfer explained in an interview that Murphy thought he had their rosy-cheeked complexion. Murphy praised Colfer's abilities despite his lack of formal training, saying, "I just thought he was so talented and gifted and unusual. I've never seen anyone who looks like him or acts like him or sounds like him. You'd think he'd been at Juilliard for six years but he hasn't." Murphy saw something of himself in the young actor, a fact that Colfer says is "completely mind-blowing". Colfer added, "For him to see me in him, I can't even describe it."

After being cast, Colfer said that he was happy "to be a part of something that is so new and different and so needed at this time", and added, "It's good to have something positive, especially for kids in small towns, like myself, who need a little pick-me-up." Kurt has twice been portrayed as a child: in the episode "Grilled Cheesus", a series of flashback scenes show Kurt at the age of eight, in which the character is played by Adam Kolkin. Although Kolkin was thirteen at the time of the audition, which called for an eight-year-old, he was chosen in part because his resemblance to Colfer was "so uncanny even the casting directors were taken aback". Kurt has also been shown even younger—in the episode "The Substitute", club director Will Schuester (Matthew Morrison) comes down with the flu and has a hallucination of the students as preschoolers; all twelve glee club members, including Kurt, are played by very young children.

In December 2010, Murphy announced that the cast of Glee would be replaced at the end of the third season to coincide with their graduation. He said, "Every year we're going to populate a new group. There's nothing more depressing than a high schooler with a bald spot." He also revealed that some of the original cast would leave as early as 2012: "I think you have to be true to the fact that here is a group of people who come and go in these teachers' lives." Murphy stated in July 2011 that Colfer would be one of the actors leaving at the end of the third season, and Colfer commented on the report, saying, "We had kind of known since the beginning, since we started the show, that these characters were going to grow up and they were going to graduate eventually. I don't think I thought it was going to happen so soon, necessarily, but I think we knew something like this was coming." However, Falchuk later said that while Colfer, along with Lea Michele and Cory Monteith, would graduate at the end of the third season, their graduation did not mean that they would leave the show. Falchuk insisted that "it was never our plan or our intention to let them go.... They are not done with the show after this season."

In the show's pilot episode, Kurt auditions for the New Directions glee club by performing "Mr. Cellophane" from Chicago. Although he initially hides his homosexuality, many of the other members assume he is gay. He confides that he is gay to fellow glee club member Mercedes (Amber Riley) in "Acafellas", and the two develop a close friendship. In the following episode, "Preggers", Kurt joins the school football team as a kicker in order to impress his widowed father, Burt Hummel (Mike O'Malley), and helps the failing team win its first game by kicking the tie-breaking extra point. His heightened confidence leads him to disclose his sexuality to his father, who not only responds with love and acceptance, but also surprises Kurt by telling him that he has long been aware that Kurt was gay. Kurt quits the football team in "Mash-Up", when Coach Ken Tanaka (Patrick Gallagher) forces the glee club members of the team to choose between the club and the team.

Kurt competes against the glee club's star singer Rachel Berry (Lea Michele) for a solo on "Defying Gravity" from the musical Wicked. However, after Burt receives a phone call labeling his son "a fag", Kurt intentionally misses the song's high note in order to lose the competition and save his father from further harassment. In the episode "Ballad", Kurt is teamed with club member and quarterback Finn Hudson (Cory Monteith), for whom he harbors romantic feelings. He is aware that Rachel is also attracted to Finn, and attempts to sabotage her chances with him by giving her a bad makeover. In "The Power of Madonna", Kurt and Mercedes, dissatisfied with their limited solo opportunities within the glee club, become singers for the school's cheerleading squad, the Cheerios. Although Mercedes soon resigns from the squad, Kurt stays through the National cheerleading competition, and performs a major solo in the routine that wins the Cheerios their sixth consecutive national championship.