| Old Stickfingers // Old StickfingersMidnight Hunt Art Series · 66 | Midnight Hunt Art Series | 66 | — | — |
| Old ThrushThe Hobbit · 2 | The Hobbit | 2 | Common | €0.03 |
| Old Way PhyrexianUnknown Event · RB03d | Unknown Event | RB03d | Rare | — |
| Olinda the ObliviousMystery Booster Commander Edition · 17 | Mystery Booster Commander Edition | 17 | Rare | €14.35 |
| OliphauntThe Lord of the Rings: Tales of Middle-earth · 139 | The Lord of the Rings: Tales of Middle-earth | 139 | Common | €0.16 |
| OliphauntThe Lord of the Rings: Tales of Middle-earth · 426 | The Lord of the Rings: Tales of Middle-earth | 426 | Common | $0.16 |
| OliphauntThe Lord of the Rings: Tales of Middle-earth · 590 | The Lord of the Rings: Tales of Middle-earth | 590 | Common | $1.52 |
| OliphauntThe Hobbit Eternal · 199 | The Hobbit Eternal | 199 | Common | $0.71 |
| Olivia, Crimson BrideInnistrad: Double Feature · 512 | Innistrad: Double Feature | 512 | Mythic Rare | €7.86 |
| Olivia, Crimson BrideInnistrad: Crimson Vow Promos · 245p | Innistrad: Crimson Vow Promos | 245p | Mythic Rare | €7.00 |
| Olivia, Crimson BrideInnistrad: Crimson Vow Promos · 245s | Innistrad: Crimson Vow Promos | 245s | Mythic Rare | €7.76 |
| Olivia, Crimson BrideInnistrad: Crimson Vow · 245 | Innistrad: Crimson Vow | 245 | Mythic Rare | €7.28 |
| Olivia, Crimson BrideInnistrad: Crimson Vow · 315 | Innistrad: Crimson Vow | 315 | Mythic Rare | €10.45 |
| Olivia, Crimson BrideInnistrad: Crimson Vow · 343 | Innistrad: Crimson Vow | 343 | Mythic Rare | $8.39 |
| Olivia, Crimson Bride // Olivia, Crimson BrideCrimson Vow Art Series · 65 | Crimson Vow Art Series | 65 | — | — |
| Olivia, Mobilized for WarShadows over Innistrad Promos · 248s | Shadows over Innistrad Promos | 248s | Mythic Rare | €3.67 |
| Olivia, Mobilized for WarSecret Lair Drop Tokens · 492 | Secret Lair Drop Tokens | 492 | Mythic Rare | €9.75 |
| Olivia, Mobilized for WarShadows over Innistrad · 248 | Shadows over Innistrad | 248 | Mythic Rare | $0.63 |
| Olivia, Mobilized for WarSecret Lair Drop Tokens · 699 | Secret Lair Drop Tokens | 699 | Mythic Rare | €2.37 |
| Olivia, Mobilized for WarThe List Tokens · SOI-248 | The List Tokens | SOI-248 | Mythic Rare | €1.46 |
| Olivia, Mobilized for WarShadows over Innistrad Remastered · 239 | Shadows over Innistrad Remastered | 239 | Mythic Rare | — |
| Olivia, Opulent OutlawOutlaws of Thunder Junction Commander · 2 | Outlaws of Thunder Junction Commander | 2 | Mythic Rare | €3.60 |
| Olivia's AttendantsInnistrad: Double Feature · 439 | Innistrad: Double Feature | 439 | Rare | €0.36 |
| Olivia's AttendantsInnistrad: Crimson Vow Promos · 172s | Innistrad: Crimson Vow Promos | 172s | Rare | €0.88 |
| Olivia's AttendantsInnistrad: Crimson Vow · 172 | Innistrad: Crimson Vow | 172 | Rare | €0.32 |
| Olivia's AttendantsInnistrad: Crimson Vow · 307 | Innistrad: Crimson Vow | 307 | Rare | $0.37 |
| Olivia's Attendants // Olivia's AttendantsCrimson Vow Art Series · 47 | Crimson Vow Art Series | 47 | — | — |
| Olivia's BloodswornThe List Tokens · SOI-127 | The List Tokens | SOI-127 | Uncommon | $0.09 |
| Olivia's BloodswornShadows over Innistrad · 127 | Shadows over Innistrad | 127 | Uncommon | €0.13 |
| Olivia's BloodswornShadows over Innistrad Remastered · 127 | Shadows over Innistrad Remastered | 127 | Uncommon | — |
| Olivia's DragoonEldritch Moon · 100 | Eldritch Moon | 100 | Common | €0.08 |
| Olivia's DragoonInnistrad Remastered · 127 | Innistrad Remastered | 127 | Common | €0.11 |
| Olivia's DragoonUltimate Masters · 109 | Ultimate Masters | 109 | Common | €0.04 |
| Olivia's DragoonShadows over Innistrad Remastered · 128 | Shadows over Innistrad Remastered | 128 | Common | — |
| Olivia's Midnight AmbushInnistrad: Double Feature · 118 | Innistrad: Double Feature | 118 | Common | €0.13 |
| Olivia's Midnight AmbushInnistrad: Midnight Hunt · 118 | Innistrad: Midnight Hunt | 118 | Common | €0.05 |
| Olivia's Midnight Ambush // Olivia's Midnight AmbushMidnight Hunt Art Series · 39 | Midnight Hunt Art Series | 39 | — | — |
| Olivia's WrathThe Lost Caverns of Ixalan Commander · 205 | The Lost Caverns of Ixalan Commander | 205 | Rare | $0.49 |
| Olivia's WrathCrimson Vow Commander · 20 | Crimson Vow Commander | 20 | Rare | $0.54 |
| Olivia's WrathCrimson Vow Commander · 58 | Crimson Vow Commander | 58 | Rare | €0.58 |
| Olivia VoldarenInnistrad Remastered · 246 | Innistrad Remastered | 246 | Mythic Rare | €2.95 |
| Olivia VoldarenInnistrad · 215 | Innistrad | 215 | Mythic Rare | €2.70 |
| Olivia VoldarenInnistrad Remastered · 490 | Innistrad Remastered | 490 | Mythic Rare | €4.95 |
| Olivia VoldarenModern Masters 2017 · 177 | Modern Masters 2017 | 177 | Mythic Rare | €2.54 |
| Olivia VoldarenSecret Lair Drop Tokens · 1264 | Secret Lair Drop Tokens | 1264 | Mythic Rare | €7.12 |
| Ollenbock EscortInnistrad: Double Feature · 294 | Innistrad: Double Feature | 294 | Uncommon | €0.16 |
| Ollenbock EscortInnistrad: Crimson Vow · 27 | Innistrad: Crimson Vow | 27 | Uncommon | €0.08 |
| Olog-hai CrusherThe Lord of the Rings: Tales of Middle-earth · 140 | The Lord of the Rings: Tales of Middle-earth | 140 | Common | €0.04 |
| Olog-hai CrusherThe Lord of the Rings: Tales of Middle-earth · 591 | The Lord of the Rings: Tales of Middle-earth | 591 | Common | €0.20 |
| Olog-hai CrusherThe Hobbit Eternal · 200 | The Hobbit Eternal | 200 | Common | $0.45 |