| Origin of Spider-ManMarvel's Spider-Man Promos · 9s | Marvel's Spider-Man Promos | 9s | Rare | $0.97 |
| Origin of Spider-ManMarvel's Spider-Man · 9 | Marvel's Spider-Man | 9 | Rare | $0.36 |
| Origin of Spider-ManMarvel's Spider-Man · 218 | Marvel's Spider-Man | 218 | Rare | €0.28 |
| Origin of Spider-ManThrough the Omenpaths · 14 | Through the Omenpaths | 14 | Rare | — |
| Origin of the AvengersMarvel Super Heroes · 28 | Marvel Super Heroes | 28 | Rare | €0.22 |
| Origin of the AvengersMarvel Super Heroes · 298 | Marvel Super Heroes | 298 | Rare | €0.37 |
| OrimVanguard Series · 205 | Vanguard Series | 205 | Rare | €7.49 |
| Orim, Samite HealerTempest · 33 | Tempest | 33 | Rare | €1.41 |
| Orim, Samite HealerTempest Remastered · 21 | Tempest Remastered | 21 | Rare | — |
| Orim's ChantJudge Gift Cards 2008 · 1 | Judge Gift Cards 2008 | 1 | Rare | €98.16 |
| Orim's ChantModern Horizons 3 · 265 | Modern Horizons 3 | 265 | Rare | $5.52 |
| Orim's ChantModern Horizons 3 · 323 | Modern Horizons 3 | 323 | Rare | $10.72 |
| Orim's ChantPlaneshift · 11 | Planeshift | 11 | Rare | €18.19 |
| Orim's ChantThe List Tokens · PLS-11 | The List Tokens | PLS-11 | Rare | $7.81 |
| Orim's ChantSecret Lair Drop Tokens · 2669 | Secret Lair Drop Tokens | 2669 | Rare | $10.06 |
| Orim's ChantMagic Online Promos · 35072 | Magic Online Promos | 35072 | Rare | — |
| Ori, Plate StackerThe Hobbit Eternal · 6 | The Hobbit Eternal | 6 | Rare | $3.84 |
| Oriq LoremageStrixhaven: School of Mages Promos · 80p | Strixhaven: School of Mages Promos | 80p | Rare | €0.62 |
| Oriq LoremageStrixhaven: School of Mages Promos · 80s | Strixhaven: School of Mages Promos | 80s | Rare | €0.44 |
| Oriq LoremageStrixhaven: School of Mages · 80 | Strixhaven: School of Mages | 80 | Rare | €0.48 |
| Oriq LoremageStrixhaven: School of Mages · 304 | Strixhaven: School of Mages | 304 | Rare | €1.03 |
| Oriq LoremageMagic Online Promos · 90052 | Magic Online Promos | 90052 | Rare | — |
| Oriss, Samite GuardianFuture Sight · 28 | Future Sight | 28 | Rare | €0.62 |
| Ormos, Archive KeeperJumpstart · 13 | Jumpstart | 13 | Rare | €0.24 |
| Ormos, Archive KeeperThe List Tokens · JMP-13 | The List Tokens | JMP-13 | Rare | €0.45 |
| Ornate KanzashiBetrayers of Kamigawa · 157 | Betrayers of Kamigawa | 157 | Rare | €0.32 |
| Ornery TumblewaggOutlaws of Thunder Junction · 171 | Outlaws of Thunder Junction | 171 | Rare | €0.30 |
| Ornery TumblewaggOutlaws of Thunder Junction · 342 | Outlaws of Thunder Junction | 342 | Rare | €0.57 |
| Ornery TumblewaggOutlaws of Thunder Junction Promos · 171p | Outlaws of Thunder Junction Promos | 171p | Rare | €0.30 |
| Ornery TumblewaggOutlaws of Thunder Junction Promos · 171s | Outlaws of Thunder Junction Promos | 171s | Rare | $0.47 |
| OrnithopterSecret Lair Drop Tokens · 604 | Secret Lair Drop Tokens | 604 | Rare | €8.83 |
| Orochi HatcheryCommander 2015 · 260 | Commander 2015 | 260 | Rare | €0.35 |
| Orochi HatcheryChampions of Kamigawa · 266 | Champions of Kamigawa | 266 | Rare | €0.58 |
| Orochi Soul-ReaverOutlaws of Thunder Junction Commander · 22 | Outlaws of Thunder Junction Commander | 22 | Rare | $8.55 |
| Orochi Soul-ReaverOutlaws of Thunder Junction Commander · 58 | Outlaws of Thunder Junction Commander | 58 | Rare | $6.26 |
| Oros, the AvengerCommander Anthology · 188 | Commander Anthology | 188 | Rare | €0.25 |
| Oros, the AvengerCommander 2011 · 216 | Commander 2011 | 216 | Rare | €0.35 |
| Oros, the AvengerCommander 2011 Oversized · 216 | Commander 2011 Oversized | 216 | Rare | €0.30 |
| Oros, the AvengerPlanar Chaos · 161 | Planar Chaos | 161 | Rare | €0.37 |
| Oros, the AvengerPlanar Chaos Promos · 161★ | Planar Chaos Promos | 161★ | Rare | €0.37 |
| Oros, the AvengerMagic Online Promos · 31959 | Magic Online Promos | 31959 | Rare | — |
| Orthion, Hero of LavabrinkMarch of the Machine · 334 | March of the Machine | 334 | Rare | €4.90 |
| Orthion, Hero of LavabrinkMarch of the Machine · 379 | March of the Machine | 379 | Rare | €3.08 |
| Orthion, Hero of LavabrinkThe List Tokens · MOM-334 | The List Tokens | MOM-334 | Rare | €4.00 |
| Orzhov PontiffRNA Guild Kit · 43 | RNA Guild Kit | 43 | Rare | $0.18 |
| Orzhov PontiffGuildpact · 124 | Guildpact | 124 | Rare | €0.30 |
| Orzhov SignetSecret Lair Drop Tokens · 294 | Secret Lair Drop Tokens | 294 | Rare | €16.62 |
| Oscorp IndustriesMarvel's Spider-Man Promos · 182s | Marvel's Spider-Man Promos | 182s | Rare | €1.47 |
| Oscorp IndustriesMarvel's Spider-Man · 182 | Marvel's Spider-Man | 182 | Rare | €0.71 |
| Oscorp IndustriesMarvel's Spider-Man · 282 | Marvel's Spider-Man | 282 | Rare | €0.79 |