Glee (stylized as glee) is an American jukebox musical comedy-drama television series that aired on Fox in the United States from May 19, 2009, to March 20, 2015. It focuses on the New Directions, a glee club at the fictional William McKinley High School in Lima, Ohio. The club competes as a show choir while its disparate members deal with social issues, regarding sexuality, gender, race, family, teen relationships and teamwork.

The initial twelve-member main cast included Matthew Morrison as teacher Will Schuester, Jane Lynch as scheming cheerleading coach Sue Sylvester, Jayma Mays as guidance counselor Emma Pillsbury, Jessalyn Gilsig as Will's wife, Terri Schuester. Other main cast members played students, with Dianna Agron as Quinn Fabray, a popular cheerleader who experiences a teenage pregnancy; Chris Colfer as Kurt Hummel, an effeminate, openly gay boy; Kevin McHale as Artie Abrams, a boy with a physical disability; Lea Michele as Rachel Berry, an ambitious performer driven by her dreams of becoming a Broadway theatre star; Cory Monteith as Finn Hudson, the school's sometimes-slow-witted star quarterback; Amber Riley as Mercedes Jones, an aspiring vocal diva whose talents go unrecognized; Mark Salling as Noah Puckerman, a delinquent in need of direction; and Jenna Ushkowitz as Tina Cohen-Chang, a shy goth who longs to be popular. The main cast was altered throughout the series, including the addition of Naya Rivera as Santana Lopez, a sardonic and cynical cheerleader struggling with her sexuality, Harry Shum Jr. as Mike Chang, a soft-spoken dancer whose parents do not support his dreams, and Heather Morris as Brittany Pierce, a ditzy cheerleader.

The series was created by Ryan Murphy, Brad Falchuk, and Ian Brennan, the latter of whom first conceived of Glee as a film. The three wrote all of the show's episodes for the first two seasons, and Murphy and Falchuk initially served as the show's main directors. The pilot episode was broadcast on May 19, 2009, and the first season aired from September 9, 2009, to June 8, 2010. Subsequent seasons aired from September through May, while the sixth and final season aired from January to March 2015. Glee features on-screen, performance-based musical numbers selected by Murphy, who aimed to maintain a balance between show tunes and chart hits, and produced by Adam Anders and Peer Åström. Songs covered in the show were released through the iTunes Store during the week of broadcast, and a series of Glee albums have been released by Columbia Records. The music of Glee has been a commercial success, with over 36 million digital single sales and eleven million album sales worldwide through October 2011. The series' merchandise also includes DVD and Blu-ray releases, an iPad application, and karaoke games for the Wii home video game console. The cast embarked on live concert tours after filming the first and second seasons; a concert film based on the 2011 tour, produced by Murphy and directed by Kevin Tancharoen, was given limited theatrical release in August 2011.

Glee received generally favorable reviews from critics during its first season, while reception to the later five varied. It won six Primetime Emmy Awards (including acting wins for Lynch and guest stars Neil Patrick Harris and Gwyneth Paltrow, along with Murphy's direction of the pilot), four Golden Globe Awards (including two consecutive awards for Best Television Series – Musical or Comedy and acting wins for Lynch and Colfer), and the 2009 Screen Actors Guild Award for Outstanding Performance by an Ensemble in a Comedy Series, and received many other accolades. In 2011, Fox chose the show to fill the coveted time slot following the network's coverage of Super Bowl XLV.

In 2013, in the wake of Cory Monteith's death and after his tribute episode "The Quarterback" aired, Murphy announced that the sixth season would be the series' last. After 121 episodes and over 729 music performances, Glee concluded on March 20, 2015.