| Uncanny SpeedAvacyn Restored · 163 | Avacyn Restored | 163 | Common | $0.06 |
| Uncharted HavenBloomburrow · 261 | Bloomburrow | 261 | Common | €0.04 |
| Uncharted HavenFoundations · 564 | Foundations | 564 | Common | $0.09 |
| Uncharted HavenKamigawa: Neon Dynasty · 281 | Kamigawa: Neon Dynasty | 281 | Common | €0.08 |
| Uncharted VoyageFoundations · 53 | Foundations | 53 | Common | €0.08 |
| Unclaimed BirdUnknown Event · CU04 | Unknown Event | CU04 | Common | — |
| Unclaimed BlessingUnknown Event · CB11 | Unknown Event | CB11 | Common | — |
| Unclaimed CatUnknown Event · CW02 | Unknown Event | CW02 | Common | — |
| Unclaimed TanadonUnknown Event · CG07 | Unknown Event | CG07 | Common | — |
| Uncomfortable ChillFoundations Jumpstart · 111 | Foundations Jumpstart | 111 | Common | €0.09 |
| Uncomfortable ChillCore Set 2019 · 82 | Core Set 2019 | 82 | Common | €0.02 |
| Uncomfortable ChillThe List Tokens · M19-82 | The List Tokens | M19-82 | Common | €0.10 |
| Uncontrollable AngerTenth Edition · 244 | Tenth Edition | 244 | Common | €0.04 |
| Uncontrollable AngerTenth Edition · 244★ | Tenth Edition | 244★ | Common | €0.04 |
| Uncontrollable AngerChampions of Kamigawa · 195 | Champions of Kamigawa | 195 | Common | €0.03 |
| Uncontrolled InfestationScourge · 108 | Scourge | 108 | Common | €0.07 |
| Uncovered CluesDragon's Maze · 19 | Dragon's Maze | 19 | Common | $0.10 |
| Undead ButlerPioneer Masters · 117 | Pioneer Masters | 117 | Common | — |
| Undead ExecutionerAvacyn Restored · 123 | Avacyn Restored | 123 | Common | $0.04 |
| Undead LeotauShards of Alara · 90 | Shards of Alara | 90 | Common | $0.09 |
| Undead MinotaurMagic 2014 · 119 | Magic 2014 | 119 | Common | $0.03 |
| Undead ServantCore Set 2020 · 118 | Core Set 2020 | 118 | Common | €0.04 |
| Undead ServantMagic Origins · 124 | Magic Origins | 124 | Common | $0.05 |
| Undercellar MyconidCommander Legends: Battle for Baldur's Gate · 259 | Commander Legends: Battle for Baldur's Gate | 259 | Common | €0.22 |
| Undercellar MyconidFoundations Jumpstart · 150 | Foundations Jumpstart | 150 | Common | €0.24 |
| Undercellar MyconidAlchemy Horizons: Baldur's Gate · 226 | Alchemy Horizons: Baldur's Gate | 226 | Common | — |
| Undercity Dire RatFinal Fantasy · 123 | Final Fantasy | 123 | Common | €0.06 |
| Undercity ReachesMarch of the Machine Commander · 163 | March of the Machine Commander | 163 | Common | €0.23 |
| Undercity ReachesPlanechase Planes · 39 | Planechase Planes | 39 | Common | €0.80 |
| Undercity ReachesPlanechase Anthology Planes · 83 | Planechase Anthology Planes | 83 | Common | €0.43 |
| Undercity ScavengerRavnica Allegiance · 88 | Ravnica Allegiance | 88 | Common | €0.04 |
| Undercity ScroungerFoundations Jumpstart · 501 | Foundations Jumpstart | 501 | Common | €0.20 |
| Undercity ScroungerKamigawa: Neon Dynasty · 126 | Kamigawa: Neon Dynasty | 126 | Common | €0.11 |
| Undercity's EmbraceRavnica Allegiance · 89 | Ravnica Allegiance | 89 | Common | €0.04 |
| Undercity's EmbraceThe List Tokens · RNA-89 | The List Tokens | RNA-89 | Common | €0.06 |
| Undercity's EmbraceRavnica Remastered · 96 | Ravnica Remastered | 96 | Common | €0.08 |
| Undercity UprisingGuilds of Ravnica · 210 | Guilds of Ravnica | 210 | Common | €0.02 |
| Undercover CrocodelfMurders at Karlov Manor · 239 | Murders at Karlov Manor | 239 | Common | €0.05 |
| Undercover CrocodelfMurders at Karlov Manor · 239† | Murders at Karlov Manor | 239† | Common | €0.03 |
| Undercover SkrullMarvel Super Heroes · 194 | Marvel Super Heroes | 194 | Common | €0.06 |
| Underdark BasiliskAdventures in the Forgotten Realms · 208 | Adventures in the Forgotten Realms | 208 | Common | €0.11 |
| Underdark BasiliskAdventures in the Forgotten Realms · 334 | Adventures in the Forgotten Realms | 334 | Common | €0.07 |
| Underdark BasiliskAlchemy Horizons: Baldur's Gate · 227 | Alchemy Horizons: Baldur's Gate | 227 | Common | — |
| Underdark ExplorerCommander Legends: Battle for Baldur's Gate · 154 | Commander Legends: Battle for Baldur's Gate | 154 | Common | €0.12 |
| Underdog RacerUnknown Event · CG05a | Unknown Event | CG05a | Common | — |
| UnderdomeUnsanctioned · 86 | Unsanctioned | 86 | Common | €0.08 |
| Underfoot UnderdogsTarkir: Dragonstorm · 129 | Tarkir: Dragonstorm | 129 | Common | €0.11 |
| UndergrowthAlliances · 102a | Alliances | 102a | Common | €0.13 |
| UndergrowthAlliances · 102b | Alliances | 102b | Common | €0.18 |
| Undergrowth LeopardTarkir: Dragonstorm · 165 | Tarkir: Dragonstorm | 165 | Common | €0.18 |