| Oltec Cloud GuardThe Lost Caverns of Ixalan · 28 | The Lost Caverns of Ixalan | 28 | Common | €0.02 |
| Omashu CityAvatar: The Last Airbender · 275 | Avatar: The Last Airbender | 275 | Common | €0.10 |
| Omega MyrMirrodin · 223 | Mirrodin | 223 | Common | €0.07 |
| OmenPortal · 62 | Portal | 62 | Common | €0.23 |
| OmenThe List Tokens · POR-62 | The List Tokens | POR-62 | Common | €0.08 |
| Omen of the DeadTheros Beyond Death · 110 | Theros Beyond Death | 110 | Common | €0.20 |
| Omen of the ForgeTheros Beyond Death · 145 | Theros Beyond Death | 145 | Common | €0.06 |
| Omen of the HuntCommander Masters · 906 | Commander Masters | 906 | Common | €0.17 |
| Omen of the HuntTheros Beyond Death · 192 | Theros Beyond Death | 192 | Common | €0.06 |
| Omen of the SeaFoundations Jumpstart · 336 | Foundations Jumpstart | 336 | Common | €0.20 |
| Omen of the SeaThe List Tokens · THB-58 | The List Tokens | THB-58 | Common | €0.09 |
| Omen of the SeaTheros Beyond Death · 58 | Theros Beyond Death | 58 | Common | €0.11 |
| Omen of the SunCommander Masters · 831 | Commander Masters | 831 | Common | €0.13 |
| Omen of the SunThe List Tokens · THB-30 | The List Tokens | THB-30 | Common | €0.04 |
| Omen of the SunTheros Beyond Death · 30 | Theros Beyond Death | 30 | Common | €0.06 |
| Omenpath InstabilityBlack Lotus Unknown Planechase · PLA032 | Black Lotus Unknown Planechase | PLA032 | Common | — |
| OmenspeakerBattlebond · 125 | Battlebond | 125 | Common | €0.07 |
| OmenspeakerConspiracy: Take the Crown · 118 | Conspiracy: Take the Crown | 118 | Common | €0.03 |
| OmenspeakerCommander Legends · 83 | Commander Legends | 83 | Common | €0.03 |
| OmenspeakerDuel Decks: Elspeth vs. Kiora Tokens · 39 | Duel Decks: Elspeth vs. Kiora Tokens | 39 | Common | €0.05 |
| OmenspeakerCore Set 2019 · 64 | Core Set 2019 | 64 | Common | €0.06 |
| OmenspeakerThe List Tokens · BBD-125 | The List Tokens | BBD-125 | Common | €0.03 |
| OmenspeakerTheros · 57 | Theros | 57 | Common | €0.06 |
| Ominous AsylumMarvel's Spider-Man · 181 | Marvel's Spider-Man | 181 | Common | €0.06 |
| Ominous AsylumThrough the Omenpaths · 182 | Through the Omenpaths | 182 | Common | — |
| Ominous ParcelStreets of New Capenna · 241 | Streets of New Capenna | 241 | Common | €0.07 |
| Omni-Cheese PizzaTeenage Mutant Ninja Turtles · 176 | Teenage Mutant Ninja Turtles | 176 | Common | €0.11 |
| Onakke CatacombPlanechase 2012 Planes · 28 | Planechase 2012 Planes | 28 | Common | €0.61 |
| Onakke CatacombPlanechase Anthology Planes · 58 | Planechase Anthology Planes | 58 | Common | €0.29 |
| Onakke JavelineerMarch of the Machine · 156 | March of the Machine | 156 | Common | €0.02 |
| Onakke OgreCore Set 2019 · 153 | Core Set 2019 | 153 | Common | €0.03 |
| Onakke OgreCore Set 2021 · 155 | Core Set 2021 | 155 | Common | €0.02 |
| Onakke OgreThe List Tokens · M19-153 | The List Tokens | M19-153 | Common | — |
| Ondu ChampionBattle for Zendikar · 149 | Battle for Zendikar | 149 | Common | €0.08 |
| Ondu ChampionThe List Tokens · BFZ-149 | The List Tokens | BFZ-149 | Common | €0.13 |
| Ondu ClericZendikar · 30 | Zendikar | 30 | Common | $0.24 |
| Ondu GiantDuel Decks: Zendikar vs. Eldrazi Tokens · 19 | Duel Decks: Zendikar vs. Eldrazi Tokens | 19 | Common | €0.15 |
| Ondu GiantJumpstart 2022 · 698 | Jumpstart 2022 | 698 | Common | €0.14 |
| Ondu GiantPlanechase Anthology · 71 | Planechase Anthology | 71 | Common | €0.04 |
| Ondu GiantPlanechase 2012 · 71 | Planechase 2012 | 71 | Common | €0.13 |
| Ondu GiantThe List Tokens · PCA-71 | The List Tokens | PCA-71 | Common | €0.10 |
| Ondu GiantRise of the Eldrazi · 202 | Rise of the Eldrazi | 202 | Common | €0.07 |
| Ondu GreathornBattle for Zendikar · 40 | Battle for Zendikar | 40 | Common | $0.03 |
| Ondu GreathornThe List Tokens · BFZ-40 | The List Tokens | BFZ-40 | Common | €0.06 |
| Ondu War ClericOath of the Gatewatch · 31 | Oath of the Gatewatch | 31 | Common | €0.06 |
| Ondu War ClericThe List Tokens · OGW-31 | The List Tokens | OGW-31 | Common | €0.11 |
| One-Clown BandUnfinity · 117 | Unfinity | 117 | Common | $0.07 |
| One-Clown BandUnfinity · 403 | Unfinity | 403 | Common | €0.27 |
| One Does NotUnknown Event · CU12a | Unknown Event | CU12a | Common | $15.00 |
| One-Eyed ScarecrowInnistrad · 230 | Innistrad | 230 | Common | $0.21 |