According to the Wikipedia list of songs in Glee, the following songs were performed more than once on Glee.
A House is Not a Home (Dionne Warwick)
- 1x16 - Home - Kurt Hummel with Finn Hudson
- 1x16 - Home - April Rhodes and Will Schuester
(as part of a mash-up with Barbra Streisand's One Less Bell to Answer)
All by Myself (Eric Carmen)
- 1x02 - Showmance - Emma Pilsbury
(short flashback scene, crying in her car, singing along to the radio)
- 2x17 - A Night of Neglect - Sunshine Corazon
(singing the Céline Dion version)
And I Am Telling You I'm Not Going (Dreamgirls)
- 1x13 - Sectionals - Mercedes Jones
- 1x13 - Sectionals - Jane Addams Girls Choir
Big Spender (Sweet Charity)
- 1x19 - Dream On - (auditioning woman)
- 3x01 - The Purple Piano Project - Sugar Motta
(her audition song)
Daydream Believer (The Monkees)
- 1x19 - Dream On - Bryan Ryan
- 6x13 - Dreams Come True - Kurt Hummel and Blaine Anderson with schoolchildren
Defying Gravity (Wicked)
- 1x09 - Wheels - Kurt Hummel and Rachel Berry
- 5x12 - 100 - Mercedes Jones, Kurt Hummel and Rachel Berry
Don't Rain on My Parade (Funny Girl)
- 1x13 - Sectionals - Rachel Berry
- 3x09 - Choke - Rachel Berry
- 5x09 - Frenemies - Santana Lopez
Don't Stop Believin' (Journey)
- 1x01 - Pilot - Rachel Berry and Finn Hudson with New Directions
- 1x05 - The Rhodes Not Taken - Quinn Fabray and Finn Hudson with New Directions
- 1x13 - Sectionals - Haverbrook Deaf Choir
- 1x22 - Journey to Regionals - New Directions
- 4x19 - Sweet Dreams - Rachel Berry with original New Directions
(her musical audition)
- 5x13 - New Directions - New Directions and Will Schuester
- 6x12 - 2009 - New Directions
(using footage from 1x01)
I Kissed a Girl (Katy Perry)
- 1x01 - Pilot - Tina Cohen-Chang
- 3x07 - I Kissed a Girl - Santana Lopez and Rachel Berry with Tina Cohen-Chang, Quinn Fabray, Mercedes Jones, Sugar Motta and Brittany Pierce
- 6x12 - 2009 - Tina Cohen-Chang
(the audition in 1x01, using new footage)
I'll Stand by You (The Pretenders)
- 1x10 - Ballad - Finn Hudson
- 5x03 - The Quarterback - Mercedes Jones with New Directions
I'm the Greatest Star (Funny Girl)
- 3x02 - I Am Unicorn - Kurt Hummel
- 5x17 - Opening Night - Rachel Berry
Keep Holding On (Avril Lavigne)
- 1x07 - Throwdown - New Directions
- 5x12 - 100 - Noah Puckerman with original and current New Directions members
Loser Like Me
- 2x16 - Original Song - Rachel Berry, Santana Lopez, Finn Hudson and Brittany Pierce with New Directions
- 5x13 - New Directions - Blaine Anderson, Sam Evans, Tina Cohen-Chang and Artie Abrams
(acoustic version)
Mister Cellophane (Chicago)
- 1x01 - Pilot - Kurt Hummel
- 6x12 - 2009 - Kurt Hummel
(the audition in 1x01, using new footage, showing Kurt only from behind)
Piano Man (Billy Joel)
- 1x19 - Dream On - Will Schuester and Bryan Ryan
- 5x06 - Movin' Out - Blaine Anderson with Spotlight Diner patrons and employees
Proud Mary (Ike and Tina Turner)
- 1x09 - Wheels - New Directions
- 1x13 - Sectionals - Jane Addams Girls Choir
Raise Your Glass (P!nk)
- 2x16 - Original Song - Dalton Academy Warblers
- 5x12 - 100 - April Rhodes and Will Schuester with original and current New Directions members
Single Ladies (Beyoncé)
- 1x04 - Preggers - Kurt Hummel with Tina Cohen-Chang and Brittany Pierce;
- 3x22 - Goodbye - Burt Hummel with Tina Cohen-Chang and Brittany Pierce
Sit Down, You're Rockin' the Boat (Guys and Dolls)
- 1x01 - Pilot - Artie Abrams with New Directions
- 3x22 - Goodbye - Artie Abrams, Rachel Berry, Tina Cohen-Chang, Kurt Hummel and Mercedes Jones
Teenage Dream (Katy Perry)
- 2x06 - Never Been Kissed - Dalton Academy Warblers
- 4x04 - The Break Up - Blaine Anderson
(acoustic version)
That's the Way (I Like It) (KC and the Sunshine Band)
- 1x01 - Pilot - 1993 McKinley High Glee Club
(only faint audio on Emma's laptop; 6x12 2009 shows a part of this video, but not this particular song)
- 3x16 - Saturday Night Glee-ver - 1993 McKinley High Glee Club
(short flashback)
Tonight (West Side Story)
- 1x04 - Preggers - Tina Cohen-Chang
- 3x05 - The First Time - Rachel Berry and Blaine Anderson
Toxic (Britney Spears)
- 2x02 - Britney/Brittany - Brittany Pierce, Santana Lopez, Will Schuester, Rachel Berry and Tina Cohen-Chang with New Directions
- 5x12 - 100 - Quinn Fabray, Santana Lopez and Brittany Pierce
Valerie (Mark Ronson feat. Amy Winehouse)
- 2x09 - Special Education - Santana Lopez with New Directions
- 5x12 - 100 - Santana Lopez and Brittany Pierce with Mike Chang and Jake Puckerman
You're the One That I Want (Grease)
- 1x01 - Pilot - Rachel Berry and Finn Hudson with New Directions
- 1x11 - Hairography - Rachel Berry and Finn Hudson
(in Rachel's room)
- 4x06 - Glease - Ryder Lynn, Marley Rose, Finn Hudson, Rachel Berry, Santana Lopez, Blaine Anderson, Kurt Hummel and Brittany Pierce
(includes flashbacks to the 1x01 performance)
The only songs performed more than twice are
- Don't Stop Believin' (5x), one performance reuses old footage
- Don't Rain on My Parade (3x), one performance ends prematurely
- I Kissed a Girl (3x), two of these show the same in-universe performance, but with different footage
- You're the One That I Want (3x), two of these performances end prematurely
