| Oblivion RingMagic Online Theme Decks · B8 | Magic Online Theme Decks | B8 | Common | — |
| Oblivion RingMagic Online Theme Decks · A12 | Magic Online Theme Decks | A12 | Common | — |
| Oblivion RingMagic Online Promos · 36202 | Magic Online Promos | 36202 | Common | — |
| Oblivion's HungerZendikar Rising · 119 | Zendikar Rising | 119 | Common | €0.08 |
| Oblivion StrikeOath of the Gatewatch · 75 | Oath of the Gatewatch | 75 | Common | $0.04 |
| Oblivion StrikeThe List Tokens · OGW-75 | The List Tokens | OGW-75 | Common | €0.02 |
| Ob Nixilis's CrueltyJumpstart 2022 · 451 | Jumpstart 2022 | 451 | Common | €0.17 |
| Ob Nixilis's CrueltyWar of the Spark · 101 | War of the Spark | 101 | Common | €0.03 |
| Ob Nixilis's CrueltyPioneer Masters · 100 | Pioneer Masters | 100 | Common | — |
| Oboro BreezecallerSaviors of Kamigawa · 48 | Saviors of Kamigawa | 48 | Common | €0.42 |
| Obscura InitiateStreets of New Capenna · 50 | Streets of New Capenna | 50 | Common | $0.02 |
| Obscura StorefrontDuskmourn: House of Horror Commander · 291 | Duskmourn: House of Horror Commander | 291 | Common | €0.20 |
| Obscura StorefrontStreets of New Capenna · 252 | Streets of New Capenna | 252 | Common | $0.29 |
| Observant AlseidTheros · 24 | Theros | 24 | Common | €0.07 |
| Obsessive SearchDominaria Remastered · 61 | Dominaria Remastered | 61 | Common | €0.12 |
| Obsessive SearchTorment · 43 | Torment | 43 | Common | €0.24 |
| Obsessive SearchVintage Masters · 83 | Vintage Masters | 83 | Common | — |
| Obsessive SkinnerShadows over Innistrad Remastered · 207 | Shadows over Innistrad Remastered | 207 | Common | — |
| Obsianus GolemMasters Edition IV · 218 | Masters Edition IV | 218 | Common | — |
| Obsidian AcolyteInvasion · 22 | Invasion | 22 | Common | $0.34 |
| Obstinate GargoyleModern Horizons 3 · 195 | Modern Horizons 3 | 195 | Common | €0.14 |
| Obyra's Attendants // Desperate ParryWilds of Eldraine · 63 | Wilds of Eldraine | 63 | Common | €0.07 |
| Oceanus DragonCommander Legends: Battle for Baldur's Gate · 87 | Commander Legends: Battle for Baldur's Gate | 87 | Common | €0.12 |
| OctoprophetJumpstart · 161 | Jumpstart | 161 | Common | €0.04 |
| OctoprophetJumpstart 2022 · 329 | Jumpstart 2022 | 329 | Common | $0.11 |
| OctoprophetCore Set 2020 · 70 | Core Set 2020 | 70 | Common | €0.09 |
| OctoprophetArena Beginner Set · 29 | Arena Beginner Set | 29 | Common | — |
| Octopus FormAvatar: The Last Airbender · 66 | Avatar: The Last Airbender | 66 | Common | €0.08 |
| Ocular HaloDissension · 28 | Dissension | 28 | Common | €0.07 |
| OculusMirrodin Besieged · 29 | Mirrodin Besieged | 29 | Common | €0.10 |
| Oculus WhelpMarch of the Machine · 69 | March of the Machine | 69 | Common | €0.03 |
| Odious TrowEventide · 125 | Eventide | 125 | Common | €0.08 |
| OffalsnoutUltimate Masters · 108 | Ultimate Masters | 108 | Common | €0.06 |
| Off BalanceNemesis · 15 | Nemesis | 15 | Common | €0.05 |
| Offender at LargeMurders at Karlov Manor · 138 | Murders at Karlov Manor | 138 | Common | €0.08 |
| Offer ImmortalityFoundations · 525 | Foundations | 525 | Common | €0.19 |
| Offer ImmortalityPhyrexia: All Will Be One · 102 | Phyrexia: All Will Be One | 102 | Common | €0.08 |
| Offering to AshaAlara Reborn · 9 | Alara Reborn | 9 | Common | €0.03 |
| Of One MindIkoria: Lair of Behemoths · 60 | Ikoria: Lair of Behemoths | 60 | Common | $0.27 |
| Oggyar Battle-SeerStrixhaven: School of Mages · 209 | Strixhaven: School of Mages | 209 | Common | €0.04 |
| Ogre BerserkerPortal Second Age · 111 | Portal Second Age | 111 | Common | €0.04 |
| Ogre ErrantThrone of Eldraine · 132 | Throne of Eldraine | 132 | Common | $0.06 |
| Ogre GatecrasherDissension · 67 | Dissension | 67 | Common | $0.02 |
| Ogre GatecrasherThe List Tokens · DIS-67 | The List Tokens | DIS-67 | Common | $0.04 |
| Ogre JailbreakerModern Masters 2017 · 80 | Modern Masters 2017 | 80 | Common | $0.02 |
| Ogre JailbreakerReturn to Ravnica · 72 | Return to Ravnica | 72 | Common | €0.04 |
| Ogre LeadfootMirrodin · 102 | Mirrodin | 102 | Common | $0.03 |
| Ogre MenialNew Phyrexia · 89 | New Phyrexia | 89 | Common | $0.08 |
| Ogre ResisterMirrodin Besieged · 72 | Mirrodin Besieged | 72 | Common | €0.03 |
| Ogre SavantDuel Decks: Ajani vs. Nicol Bolas · 55 | Duel Decks: Ajani vs. Nicol Bolas | 55 | Common | €0.07 |