| Song Title | Source | Composer(s) |
|---|
| O Admirabile | Troubadour
| Holder |
| O Brave Fat Lady | Joker Of Seville, The
| MacDermot |
| O Come All Ye Faithful | Black Nativity
| various |
| O Cruel, Cruel Case! | Beggar's Opera, The
| Gay |
| O Foolish Heart | Green Bird, The
| Goldenthal |
| O Greedy People (The Apples That Sing) | Green Bird, The
| Goldenthal |
| O Happy Day | Blue Moon Experience
| various |
| O Have You Ever Been To China? | Fantasticks, The
| Schmidt |
| O Hett I Flügel | Schwarze Hecht, Der
| Burkhard |
| O Little Red Bird | Joker Of Seville, The
| MacDermot |
| O Marry Me! | O Marry Me!
| Kessler |
| O Mein Papa! | Schwarze Hecht, Der
| Burkhard |
| O Mio Bambino, Callas |
| |
| O Miserere | Candide
| Bernstein |
| O Mistress Mine | Karl Marx Play, The
| MacDermot |
| O Pallas Athene | Sing Muse!
| Raposo |
| O Peaceful England | Merrie England
| German |
| O Polly, You Might Have Toyed And Kissed | Beggar's Opera, The
| Gay |
| O Ponder Well | Beggar's Opera, The
| Gay |
| O Say Can You See! | O say can you see!
| Holmes |
| O Servito a Signor Crudele | Atylantos
| Capdevielle |
| O Shadow | Warrior Ant, The
| Telson |
| O Signorina | Käpt'n Bay Bay
| Schulze |
| O Sole Mio | Lanza: the Last Serenade
| various |
| O Take This Ancient Mansion | Virtue in Danger
| Bernard |
| O Tannenbaum | Sueño De Navidad, Un
| Murillo |
| O Tixo, Tixo, Help Me | Lost in the Stars
| Weill |
| O War Zalig Om Es Neer Te Kijken | Publiek
| Zimmerman |
| O' Sanity | New York Rock
| Ono |
| O'Brien Has Gone Hawaiian | Song of the Islands
| Owens |
| O'Brien to Ryan to Goldberg | Take Me Out to the Ball Game
| Edens |
| O, Grenada | Rap Master Ronnie
| Swados |
| O, Where the Deer Do Lie | Merrie England
| German |
| O-Todd-Ao | Forbidden Hollywood
| various, Alessandrini |
| O.H.M.S. | Cambridge Circus
| McDonald, Oddie |
| Oak and the Ash, The | Half a Sixpence
| Heneker |
| Oasis Catalan, El | Flor de nit
| Guinovart |
| Oath of Don Joaquin, The | My Cousin Josefa
| Austin |
| Oath of Office | In Spite of Reason
| Cavallo, Doucette |
| Oath, The | Happiest Girl In The World, The
| Offenbach |
| Obercool | Tankstelle Der Verdammten, Die
| Ringsgwandl |
| Obeying Father | Bei Mir Bistu Schoen
| Secunda |
| Obituary | Ten Percent Revue
| Weinberg |
| Object Is to Win, The | Jack the Musical
| Holt |
| Objection | Captive
| Collister |
| Obladi-Oblada | Norwegian Wood
| Lennon, McCartney |
| Obsessed | Hard Time To Be Single, A
| Gari |
| Obsessed | Late Nite Comic
| Gari |
| Obsession | Jekyll & Hyde
| Wildhorn |
| Ocarina, The | Call Me Madam
| Berlin |
