| Occult EpiphanyReality Fracture Commander · 43 | Reality Fracture Commander | 43 | Rare | $0.22 |
| Occupation of KulrathUnknown Event · RR02b | Unknown Event | RR02b | Rare | $4.99 |
| Occupation of LlanowarUnknown Event · RG11 | Unknown Event | RG11 | Rare | $100.00 |
| Oceanus DragonCommander Legends: Battle for Baldur's Gate · 87 | Commander Legends: Battle for Baldur's Gate | 87 | Common | €0.13 |
| Ocelot PrideModern Horizons 3 · 38 | Modern Horizons 3 | 38 | Mythic Rare | €38.24 |
| Ocelot PrideModern Horizons 3 · 322 | Modern Horizons 3 | 322 | Mythic Rare | €72.54 |
| Ocelot PrideModern Horizons 3 · 394 | Modern Horizons 3 | 394 | Mythic Rare | $46.17 |
| Ocelot PrideModern Horizons 3 Promos · 38p | Modern Horizons 3 Promos | 38p | Mythic Rare | €39.03 |
| Ocelot PrideModern Horizons 3 Promos · 38s | Modern Horizons 3 Promos | 38s | Mythic Rare | €51.05 |
| Ocelot PrideStore Championships · 47 | Store Championships | 47 | Rare | €127.47 |
| Ochran AssassinGuilds of Ravnica · 194 | Guilds of Ravnica | 194 | Uncommon | €0.08 |
| Ochran AssassinThe List Tokens · GRN-194 | The List Tokens | GRN-194 | Uncommon | €0.27 |
| Ochre JellyAdventures in the Forgotten Realms · 196 | Adventures in the Forgotten Realms | 196 | Rare | $0.40 |
| Ochre JellyAdventures in the Forgotten Realms · 330 | Adventures in the Forgotten Realms | 330 | Rare | $0.38 |
| Ochre JellyAdventures in the Forgotten Realms Promos · 196a | Adventures in the Forgotten Realms Promos | 196a | Rare | €0.90 |
| Ochre JellyAdventures in the Forgotten Realms Promos · 196p | Adventures in the Forgotten Realms Promos | 196p | Rare | €0.38 |
| Ochre JellyAdventures in the Forgotten Realms Promos · 196s | Adventures in the Forgotten Realms Promos | 196s | Rare | €0.94 |
| Octavia, Living ThesisCommander 2021 · 29 | Commander 2021 | 29 | Rare | €0.24 |
| Octavia, Living ThesisCommander 2021 · 356 | Commander 2021 | 356 | Rare | €1.72 |
| Octavia, Living ThesisOutlaws of Thunder Junction Commander · 103 | Outlaws of Thunder Junction Commander | 103 | Rare | €0.74 |
| Octavia, Living ThesisMagic Online Promos · 90026 | Magic Online Promos | 90026 | Rare | — |
| OctomancerBloomburrow Commander · 37 | Bloomburrow Commander | 37 | Rare | $0.36 |
| OctomancerBloomburrow Commander · 69 | Bloomburrow Commander | 69 | Rare | €1.22 |
| Octo OpusUnfinity · 54 | Unfinity | 54 | Uncommon | $0.06 |
| Octo OpusUnfinity · 340 | Unfinity | 340 | Uncommon | $0.36 |
| OctoprophetJumpstart · 161 | Jumpstart | 161 | Common | €0.07 |
| OctoprophetJumpstart 2022 · 329 | Jumpstart 2022 | 329 | Common | $0.11 |
| OctoprophetCore Set 2020 · 70 | Core Set 2020 | 70 | Common | €0.07 |
| OctoprophetArena Beginner Set · 29 | Arena Beginner Set | 29 | Common | — |
| OctopusBattle for Zendikar Tokens · 7 | Battle for Zendikar Tokens | 7 | — | $0.19 |
| OctopusBloomburrow Commander Tokens · 14 | Bloomburrow Commander Tokens | 14 | — | — |
| Octopus FormAvatar: The Last Airbender · 66 | Avatar: The Last Airbender | 66 | Common | €0.11 |
| Octopus UmbraCommander 2018 · 11 | Commander 2018 | 11 | Rare | €0.39 |
| Octopus UmbraThe List Tokens · C18-11 | The List Tokens | C18-11 | Rare | €1.68 |
| Octopus UmbraTreasure Chest · 70725 | Treasure Chest | 70725 | Rare | — |
| Ocular HaloDissension · 28 | Dissension | 28 | Common | €0.08 |
| OculusMirrodin Besieged · 29 | Mirrodin Besieged | 29 | Common | €0.09 |
| Oculus WhelpMarch of the Machine · 69 | March of the Machine | 69 | Common | €0.06 |
| Oculus Whelp // Oculus WhelpMarch of the Machine Art Series · 15 | March of the Machine Art Series | 15 | — | — |
| Oddly UnevenThe List (Unfinity Foil Edition) · 6 | The List (Unfinity Foil Edition) | 6 | Rare | $0.23 |
| Oddly UnevenUnstable · 15 | Unstable | 15 | Rare | €0.21 |
| Oddric, Lunar MarquisMystery Booster 2 Tokens · 551 | Mystery Booster 2 Tokens | 551 | Rare | $0.15 |
| Odds // EndsDissension · 153 | Dissension | 153 | Rare | €0.27 |
| Odds // EndsThe List Tokens · DIS-153 | The List Tokens | DIS-153 | Rare | €0.21 |
| Odious TrowEventide · 125 | Eventide | 125 | Common | €0.08 |
| Odric, Blood-CursedInnistrad: Double Feature · 510 | Innistrad: Double Feature | 510 | Rare | €0.19 |
| Odric, Blood-CursedInnistrad: Crimson Vow Promos · 243s | Innistrad: Crimson Vow Promos | 243s | Rare | €0.66 |
| Odric, Blood-CursedInnistrad: Crimson Vow · 243 | Innistrad: Crimson Vow | 243 | Rare | €0.20 |
| Odric, Blood-CursedInnistrad: Crimson Vow · 314 | Innistrad: Crimson Vow | 314 | Rare | €0.24 |
| Odric, Blood-Cursed // Odric, Blood-CursedCrimson Vow Art Series · 64 | Crimson Vow Art Series | 64 | — | — |