The second season of the musical comedy-drama television series Glee originally aired between September 21, 2010, and May 24, 2011, on Fox in the United States.

The series features the New Directions glee club at the fictional William McKinley High School in the town of Lima, Ohio.

Season two follows the club competing on the show choir circuit, while its members and faculty deal with sex, religion, homophobia, financial difficulties, rumors, teenage drinking, death and other social issues.

The central characters are glee club director Will Schuester (Matthew Morrison), cheerleading coach Sue Sylvester (Jane Lynch), guidance counselor Emma Pillsbury (Jayma Mays), and glee club members Artie Abrams (Kevin McHale), Brittany Pierce (Heather Morris), Finn Hudson (Cory Monteith), Kurt Hummel (Chris Colfer), Mercedes Jones (Amber Riley), Noah "Puck" Puckerman (Mark Salling), Quinn Fabray (Dianna Agron), Rachel Berry (Lea Michele), Santana Lopez (Naya Rivera) and Tina Cohen-Chang (Jenna Ushkowitz).

Will's ex-wife Terri (Jessalyn Gilsig) and Kurt's father Burt (Mike O'Malley) round out the list of main characters.

The cast decisively broke the record for most charted songs by an act in the 52-year history of the Billboard Hot 100 with 156 appearances through the end of its second season.

Two singles, "Teenage Dream" and "Loser like Me", were the first to have over 200,000 downloads in their first week of release in the US, and both charted in the top ten in the US and Canada, and have been certified gold in the US.

"[34] Not all of his plans came to fruition; in July 2010, Murphy claimed that glee club co-captains Finn and Rachel would remain in a relationship throughout the season,[35] however this was abandoned in favor of a love-triangle storyline to generate conflict.

[36] One unintended development was the emergence of Kurt as a central character—his role grew in prominence as a result of the writers' desire to do justice to the gay bullying storyline.

[31][43] The twelve main cast members from the first season returned for the second: Matthew Morrison as glee club director Will Schuester, Jane Lynch as cheerleading coach Sue Sylvester, Jayma Mays as guidance counselor Emma Pillsbury, Jessalyn Gilsig as Will's former wife Terri Schuester and Dianna Agron, Chris Colfer, Kevin McHale, Lea Michele, Cory Monteith, Amber Riley, Mark Salling and Jenna Ushkowitz as glee club members Quinn Fabray, Kurt Hummel, Artie Abrams, Rachel Berry, Finn Hudson, Mercedes Jones, Noah "Puck" Puckerman and Tina Cohen-Chang, respectively.

[23] Heather Morris and Naya Rivera, who portrayed the formerly recurring roles of Brittany Pierce and Santana Lopez, were promoted to series regulars,[44] as was Mike O'Malley as Kurt's father Burt Hummel.

[49][50] Returning secondary characters included Iqbal Theba as Principal Figgins, Stephen Tobolowsky as former glee club director Sandy Ryerson, Romy Rosemont as Finn's mother Carole Hudson, Max Adler as school bully Dave Karofsky and James Earl as his fellow bully Azimio, Josh Sussman as school reporter Jacob Ben Israel, Lauren Potter as cheerleader Becky Jackson, Jonathan Groff as Rachel's ex-boyfriend Jesse St. James, and Kristin Chenoweth as former glee club star April Rhodes.

[40][51] The season introduced several new recurring characters: Chord Overstreet was cast as transfer student Sam Evans;[52][53] Darren Criss appeared as Blaine Anderson, lead singer of rival glee club the Dalton Academy Warblers;[54] Cheyenne Jackson played Dustin Goolsby, the coach of rival glee club Vocal Adrenaline;[55] Jake Zyrus appeared as Sunshine Corazon, a foreign exchange student from the Philippines and a rival to Rachel who ultimately joins Vocal Adrenaline;[56] John Stamos played dentist Carl Howell, a love interest for Emma;[57] and Gwyneth Paltrow appeared as substitute teacher Holly Holliday.

It marked the lowest debut and sales for the cast in the United States,[79] but the highest position ever reached for a Rocky Horror album.

[88][89] "Teenage Dream" and "Loser Like Me" were the second and third cast singles to be certified Gold in the US; the first was "Don't Stop Believin'", which subsequently received its Platinum certification during the second season.

[84] The record for most appearances by a group on the Billboard Hot 100, previously set by The Beatles, was broken when six songs from the season's second episode, "Britney/Brittany", debuted on the chart the week of October 16, 2010, which put the Glee total at seventy-five.

The site's critics consensus reads, "Glee loses some of its spark in this reprise, but the series still delights with its frothy musical numbers and sensitive engagement with pressing social issues.

The Parents Television Council named "Britney/Brittany", "Blame It on the Alcohol" and "Sexy" the worst shows of their respective weeks of broadcast, due to their overt sexual content.

[104] "Sexy" was also criticized by the children's charity Kidscape for the "wholly inappropriate" inclusion of a song by convicted sex offender Gary Glitter.

No other show on TV features a cast this diverse: people of color, sexual others, different body types, gender subversion and even the disabled.

"[108] The season premiere episode, "Audition", aired on September 21, 2010; it averaged 12.45 million American viewers and achieved a 5.6/16 Nielsen rating/share in the 18–49 demographic.

The second episode, which featured the music of Britney Spears, was also Glee's second best showing at that point after its April 2010 return after a four-month hiatus, with 13.51 million viewers and a 5.9/17 rating/share in the 18–49 demographic.

[114][115] A mid-season feature story in The Hollywood Reporter, which ran on January 25, 2011, stated that Glee had become the most-watched program of US origin in the UK.