| Undergrowth ScavengerMagic 2015 · 204 | Magic 2015 | 204 | Common | €0.10 |
| Undersea InvaderKaldheim · 78 | Kaldheim | 78 | Common | €0.06 |
| Undersea InvaderJumpstart 2022 · 366 | Jumpstart 2022 | 366 | Common | €0.14 |
| Undersea InvaderFoundations Jumpstart · 380 | Foundations Jumpstart | 380 | Common | €0.13 |
| UndersimplifyAlchemy Horizons: Baldur's Gate · 40 | Alchemy Horizons: Baldur's Gate | 40 | Common | — |
| UndertakerMercadian Masques · 167 | Mercadian Masques | 167 | Common | $0.24 |
| Underwater Tunnel // Slimy AquariumDuskmourn: House of Horror · 79 | Duskmourn: House of Horror | 79 | Common | €0.10 |
| Underworld ChargerTheros Beyond Death · 120 | Theros Beyond Death | 120 | Common | €0.06 |
| Underworld Rage-HoundTheros Beyond Death · 163 | Theros Beyond Death | 163 | Common | €0.04 |
| UndoVisions · 47 | Visions | 47 | Common | €0.11 |
| Undulating WitnessReality Fracture · 45 | Reality Fracture | 45 | Common | €0.02 |
| Undying BeastPortal · 113 | Portal | 113 | Common | $0.15 |
| Undying EvilDark Ascension · 77 | Dark Ascension | 77 | Common | $0.40 |
| Undying MaliceInnistrad: Double Feature · 401 | Innistrad: Double Feature | 401 | Common | €1.76 |
| Undying MaliceFoundations · 528 | Foundations | 528 | Common | $0.36 |
| Undying MaliceInnistrad: Crimson Vow · 134 | Innistrad: Crimson Vow | 134 | Common | €0.70 |
| Undying RageCommander Legends · 205 | Commander Legends | 205 | Common | €0.06 |
| Undying RageDominaria Remastered · 146 | Dominaria Remastered | 146 | Common | $0.03 |
| Undying RageEternal Masters · 152 | Eternal Masters | 152 | Common | €0.06 |
| Undying RageThe List Tokens · EMA-152 | The List Tokens | EMA-152 | Common | €0.07 |
| Undying RageUltimate Masters · 153 | Ultimate Masters | 153 | Common | €0.04 |
| UnearthDouble Masters 2022 · 96 | Double Masters 2022 | 96 | Common | $0.43 |
| UnearthDouble Masters 2022 · 357 | Double Masters 2022 | 357 | Common | $0.83 |
| UnearthMasters 25 · 113 | Masters 25 | 113 | Common | €0.41 |
| UnearthModern Horizons · 113 | Modern Horizons | 113 | Common | €0.48 |
| UnearthThe List Tokens · ULG-72 | The List Tokens | ULG-72 | Common | $0.59 |
| UnearthUrza's Legacy · 72 | Urza's Legacy | 72 | Common | $1.63 |
| UnearthHistoric Anthology 7 · 8 | Historic Anthology 7 | 8 | Common | — |
| UnearthMagic Online Promos · 102243 | Magic Online Promos | 102243 | Common | — |
| UnearthThe Zeta Set · 51 | The Zeta Set | 51 | Common | — |
| UnearthThe Zeta Set · 172 | The Zeta Set | 172 | Common | — |
| UnearthThe Zeta Set · 293 | The Zeta Set | 293 | Common | — |
| Unearthly BlizzardChampions of Kamigawa · 196 | Champions of Kamigawa | 196 | Common | €0.05 |
| Uneasy AllianceTeenage Mutant Ninja Turtles · 28 | Teenage Mutant Ninja Turtles | 28 | Common | €0.09 |
| Uneasy PartingsThe Hobbit · 58 | The Hobbit | 58 | Common | €0.07 |
| Unending WhisperTarkir: Dragonstorm · 62 | Tarkir: Dragonstorm | 62 | Common | €0.07 |
| Unexpected AlliesAlchemy Horizons: Baldur's Gate · 62 | Alchemy Horizons: Baldur's Gate | 62 | Common | — |
| Unexpected AssistanceLorwyn Eclipsed · 80 | Lorwyn Eclipsed | 80 | Common | €0.10 |
| Unexpected FangsIkoria: Lair of Behemoths · 102 | Ikoria: Lair of Behemoths | 102 | Common | $0.32 |
| Unexpected FangsThe List Tokens · IKO-102 | The List Tokens | IKO-102 | Common | $0.21 |
| Unexpected WindfallAdventures in the Forgotten Realms · 164 | Adventures in the Forgotten Realms | 164 | Common | $2.68 |
| Unexpected WindfallFallout · 193 | Fallout | 193 | Common | $2.95 |
| Unexpected WindfallFallout · 721 | Fallout | 721 | Common | €18.06 |
| Unexpected WindfallThe List Tokens · AFR-164 | The List Tokens | AFR-164 | Common | $3.66 |
| Unexpected WindfallAlchemy Horizons: Baldur's Gate · 192 | Alchemy Horizons: Baldur's Gate | 192 | Common | — |
| Unexpected WindfallThrough the Omenpaths Bonus Sheet · 29 | Through the Omenpaths Bonus Sheet | 29 | Common | — |
| Unexpected WindfallFoundations Commander · 184 | Foundations Commander | 184 | Common | $1.94 |
| Unexplained DisappearanceGuilds of Ravnica · 56 | Guilds of Ravnica | 56 | Common | €0.13 |
| Unexplained VisionThrone of Eldraine · 70 | Throne of Eldraine | 70 | Common | €0.11 |
| Unfathomable TruthsModern Horizons 3 · 77 | Modern Horizons 3 | 77 | Common | €0.12 |