| Oscorp Research TeamThrough the Omenpaths · 40 | Through the Omenpaths | 40 | Common | — |
| Osgir, the ReconstructorCommander 2021 · 8 | Commander 2021 | 8 | Mythic Rare | €0.53 |
| Osgir, the ReconstructorCommander 2021 · 335 | Commander 2021 | 335 | Mythic Rare | €2.48 |
| Osgir, the ReconstructorCommander 2021 Display Commanders · 8 | Commander 2021 Display Commanders | 8 | Mythic Rare | $0.20 |
| Osgir, the ReconstructorMagic Online Promos · 90284 | Magic Online Promos | 90284 | Mythic Rare | — |
| Osgood, Operation DoubleDoctor Who · 191 | Doctor Who | 191 | Rare | €0.25 |
| Osgood, Operation DoubleDoctor Who · 367 | Doctor Who | 367 | Rare | €0.34 |
| Osgood, Operation DoubleDoctor Who · 796 | Doctor Who | 796 | Rare | €2.66 |
| Osgood, Operation DoubleDoctor Who · 958 | Doctor Who | 958 | Rare | €0.53 |
| Osgood, Operation DoubleDoctor Who Tokens · 32 | Doctor Who Tokens | 32 | — | €0.97 |
| Osgood, Operation DoubleDoctor Who Tokens · 64 | Doctor Who Tokens | 64 | — | — |
| Oskar, Rubbish ReclaimerNew Capenna Commander · 77 | New Capenna Commander | 77 | Rare | €0.09 |
| Oskar, Rubbish ReclaimerNew Capenna Commander · 177 | New Capenna Commander | 177 | Rare | €1.10 |
| Oskar, Rubbish ReclaimerNew Capenna Commander Promos · 77p | New Capenna Commander Promos | 77p | Rare | €1.00 |
| Osseous ExhaleTarkir: Dragonstorm · 17 | Tarkir: Dragonstorm | 17 | Common | €0.10 |
| Osseous SticktwisterDuskmourn: House of Horror · 112 | Duskmourn: House of Horror | 112 | Uncommon | €0.15 |
| Osseous SticktwisterThe List Tokens · DSK-112 | The List Tokens | DSK-112 | Uncommon | — |
| OssificationPhyrexia: All Will Be One · 26 | Phyrexia: All Will Be One | 26 | Uncommon | €0.27 |
| OssificationPhyrexia: All Will Be One · 277 | Phyrexia: All Will Be One | 277 | Uncommon | €0.37 |
| OssificationCowboy Bebop · 1 | Cowboy Bebop | 1 | Rare | €1.96 |
| OssificationThe List Tokens · ONE-26 | The List Tokens | ONE-26 | Uncommon | $0.18 |
| Ossuary RatsJumpstart 2022 · 24 | Jumpstart 2022 | 24 | Common | €0.15 |
| Osteomancer AdeptBloomburrow · 103 | Bloomburrow | 103 | Rare | $0.38 |
| Osteomancer AdeptBloomburrow · 312 | Bloomburrow | 312 | Rare | €0.61 |
| Osteomancer AdeptBloomburrow Promos · 103p | Bloomburrow Promos | 103p | Rare | $0.51 |
| Osteomancer AdeptBloomburrow Promos · 103s | Bloomburrow Promos | 103s | Rare | $0.91 |
| Ostiary ThrullGuildpact · 55 | Guildpact | 55 | Common | €0.08 |
| OstracizeSeventh Edition · 153 | Seventh Edition | 153 | Common | €0.13 |
| OstracizeSeventh Edition · 153★ | Seventh Edition | 153★ | Common | $0.13 |
| OstracizeUrza's Legacy · 57 | Urza's Legacy | 57 | Common | $0.14 |
| Ostrich-HorseAvatar: The Last Airbender · 188 | Avatar: The Last Airbender | 188 | Common | €0.03 |
| Oswald FiddlebenderAdventures in the Forgotten Realms · 28 | Adventures in the Forgotten Realms | 28 | Rare | €2.14 |
| Oswald FiddlebenderAdventures in the Forgotten Realms · 304 | Adventures in the Forgotten Realms | 304 | Rare | $1.91 |
| Oswald FiddlebenderAdventures in the Forgotten Realms Promos · 28a | Adventures in the Forgotten Realms Promos | 28a | Rare | €28.20 |
| Oswald FiddlebenderAdventures in the Forgotten Realms Promos · 28p | Adventures in the Forgotten Realms Promos | 28p | Rare | €2.16 |
| Oswald FiddlebenderAdventures in the Forgotten Realms Promos · 28s | Adventures in the Forgotten Realms Promos | 28s | Rare | €3.11 |
| OtariaPlanechase Planes · 28 | Planechase Planes | 28 | Common | €2.10 |
| OtariaPlanechase Anthology Planes · 61 | Planechase Anthology Planes | 61 | Common | €0.40 |
| Otarian JuggernautOdyssey · 305 | Odyssey | 305 | Rare | €0.18 |
| Otawara, Soaring CityKamigawa: Neon Dynasty · 271 | Kamigawa: Neon Dynasty | 271 | Rare | €24.67 |
| Otawara, Soaring CityKamigawa: Neon Dynasty · 414 | Kamigawa: Neon Dynasty | 414 | Rare | €30.52 |
| Otawara, Soaring CityKamigawa: Neon Dynasty · 503 | Kamigawa: Neon Dynasty | 503 | Rare | €30.11 |
| Otawara, Soaring CityKamigawa: Neon Dynasty Promos · 271p | Kamigawa: Neon Dynasty Promos | 271p | Rare | €24.95 |
| Otawara, Soaring CityKamigawa: Neon Dynasty Promos · 271s | Kamigawa: Neon Dynasty Promos | 271s | Rare | €30.51 |
| Otawara, Soaring CityMagic Online Promos · 98123 | Magic Online Promos | 98123 | Rare | — |
| Otawara, Soaring CityMagic Online Promos · 98125 | Magic Online Promos | 98125 | Rare | — |
| OteclánBlack Lotus Unknown Planechase · PLA018 | Black Lotus Unknown Planechase | PLA018 | Common | — |
| Oteclan Landmark // Oteclan LevitatorThe Lost Caverns of Ixalan · 29 | The Lost Caverns of Ixalan | 29 | Common | €0.04 |
| Otepec HuntmasterThe Lost Caverns of Ixalan Commander · 229 | The Lost Caverns of Ixalan Commander | 229 | Uncommon | €0.10 |
| Otepec HuntmasterIxalan · 153 | Ixalan | 153 | Uncommon | $0.39 |