| Oren Lavie | Her Morning Elegance | — | 60 | Rock | A Quarter Past Wonderful | 2009 |
| Organic Audio | Good To Go | Lp Version | 129 | — | Nettwerk America | 2001 |
| Organized Konfusion | Decisions | — | 90 | — | — | — |
| Organized Konfusion | Stress | — | 89 | — | — | — |
| Organized Noise | Set It Off | — | 89 | — | — | — |
| Organized Noize | Set It Off | — | 90 | — | Eastwest Records | 1996 |
| Organized Noize | Set It Off | Silk's House Set 12" Version | 115 | — | East/west Records | 1996 |
| OriShango | Mas El Chisme Que El Dinero | — | 116 | — | — | 2020 |
| Orianthi | According To You | — | 130 | Top 40 | 19/Geffen | 2009 |
| Orianthi | According To You | The Jason Sangerman Remix | 131 | — | 19/Geffen/Interscope | 2010 |
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| Orianthi | According To You | Top 40 Edit | 131 | — | 19/Geffen/Interscope | 2009 |
| Orianthi | Shut Up & Kiss Me | — | 152 | Top 40 | 19/Geffen/Interscope | 2010 |
| Orianthi ft. Lacey From Flyleaf | Courage | — | 98 | Top 40 | 19/Geffen/Interscope | 2011 |
| Orianthi ft. Steve Vai | Highly Strung | — | 120 | — | Geffen | 2010 |
| Original 3 Feat. Corey Hart | Sunglasses At Night 2002 | Original Uv 3 Remix | 130 | — | Sony Music Canada | 2002 |
| Original Banda El Limon De Salvador Lizarraga | Hasta Mi Ultimo Dia | — | 62 | Banda | Fonovisa | 2011 |
| Original Broadway Cast Of The Prom | You Happened | The Prom: A New Musical | 65 | Top 40 | The Prom: A New Musical | 2019 |
| Original Cast Of SpongeBob SquarePants, The New Musical | (Just A) Simple Sponge | — | 75 | Top 40 | — | 2018 |
| Original Mirrors | 20,000 Dreamers | — | 131 | New Wave | — | 1981 |
| Original Position ft. Nick Name | Physical | Extenz Club Mix | 135 | — | Fakey Records | 2004 |
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| Orion Too Featuring Caitlin | Hope & Wait | Dj Euphorik Extended Club Mix | 140 | Breaks | Mostiko | 2002 |
| Orion Too Featuring Caitlin | Travelling | Extended Version | 140 | Trance | Mostiko | 2003 |
| Orion Too Featuring Caitlin | White Christmas | Rich's Club Mix | 140 | Trance | Mostiko | 2003 |
| Orishas | El Kilo | — | 80 | Latin Pop | Universal Latino | 2005 |
| Orishas | Hay Un Son | — | 100 | — | Universal Music Latino | 2007 |