| Undercity UpheavalMarch of the Machine: The Aftermath · 205 | March of the Machine: The Aftermath | 205 | Uncommon | €0.32 |
| Undercover ButlerRavnica: Clue Edition · 49 | Ravnica: Clue Edition | 49 | Uncommon | $0.17 |
| Underdark RiftForgotten Realms Commander · 62 | Forgotten Realms Commander | 62 | Uncommon | €0.10 |
| Underdark RiftThe List Tokens · AFC-62 | The List Tokens | AFC-62 | Uncommon | €0.27 |
| Underhanded DesignsKaladesh · 104 | Kaladesh | 104 | Uncommon | $0.18 |
| Underhanded DesignsKaladesh Remastered · 108 | Kaladesh Remastered | 108 | Uncommon | — |
| Under the SkinDuskmourn: House of Horror · 203 | Duskmourn: House of Horror | 203 | Uncommon | €0.13 |
| Under the SkinDuskmourn: House of Horror · 323 | Duskmourn: House of Horror | 323 | Uncommon | €0.10 |
| UndertowLegends · 82 | Legends | 82 | Uncommon | €1.49 |
| Underworld CoinsmithCommander 2015 · 237 | Commander 2015 | 237 | Uncommon | €0.15 |
| Underworld CoinsmithJourney into Nyx · 157 | Journey into Nyx | 157 | Uncommon | €0.21 |
| Underworld CoinsmithThe List Tokens · C15-237 | The List Tokens | C15-237 | Uncommon | €0.15 |
| Underworld DreamsLegends · 124 | Legends | 124 | Uncommon | $84.47 |
| Underworld DreamsTheros Beyond Death · 121 | Theros Beyond Death | 121 | Uncommon | €0.90 |
| Underworld FiresTheros Beyond Death · 162 | Theros Beyond Death | 162 | Uncommon | $0.04 |
| Underworld HermitModern Horizons 2 · 105 | Modern Horizons 2 | 105 | Uncommon | €0.12 |
| Underworld HermitModern Horizons 2 · 347 | Modern Horizons 2 | 347 | Uncommon | €0.10 |
| Underworld HermitThe List Tokens · MH2-105 | The List Tokens | MH2-105 | Uncommon | $0.12 |
| UndoPortal Second Age · 59 | Portal Second Age | 59 | Uncommon | $0.40 |
| UndoStarter 1999 · 58 | Starter 1999 | 58 | Uncommon | $0.30 |
| UndoThe List Tokens · P02-59 | The List Tokens | P02-59 | Uncommon | $0.12 |
| Undying RageDuel Decks: Heroes vs. Monsters · 26 | Duel Decks: Heroes vs. Monsters | 26 | Uncommon | €0.07 |
| Undying RageSalvat 2005 · I51 | Salvat 2005 | I51 | Uncommon | €0.04 |
| Undying RageTime Spiral · 184 | Time Spiral | 184 | Uncommon | €0.09 |
| Unerring SlingMirage · 322 | Mirage | 322 | Uncommon | $0.18 |
| Unexpected PotentialConspiracy · 12 | Conspiracy | 12 | Uncommon | €0.17 |
| Unexpected RequestFinal Fantasy · 167 | Final Fantasy | 167 | Uncommon | €0.08 |
| Unflinching CourageBattlebond · 230 | Battlebond | 230 | Uncommon | €0.13 |
| Unflinching CourageCommander 2018 · 192 | Commander 2018 | 192 | Uncommon | €0.18 |
| Unflinching CourageDragon's Maze · 111 | Dragon's Maze | 111 | Uncommon | €0.13 |
| Unflinching CourageFoundations · 722 | Foundations | 722 | Uncommon | $0.15 |
| Unflinching CourageModern Masters 2017 · 197 | Modern Masters 2017 | 197 | Uncommon | €0.18 |
| Unflinching CourageThe List Tokens · C18-192 | The List Tokens | C18-192 | Uncommon | €0.24 |
| Unflinching CouragePioneer Masters · 250 | Pioneer Masters | 250 | Uncommon | — |
| Unforgiving OneKamigawa: Neon Dynasty · 127 | Kamigawa: Neon Dynasty | 127 | Uncommon | €0.13 |
| Unforgiving OvertakeAlchemy: Aetherdrift · 11 | Alchemy: Aetherdrift | 11 | Uncommon | — |
| Unfortunate AccidentOutlaws of Thunder Junction · 111 | Outlaws of Thunder Junction | 111 | Uncommon | €0.07 |
| Unholy CitadelLegends · 309 | Legends | 309 | Uncommon | €4.61 |
| Unified FrontBattle for Zendikar · 53 | Battle for Zendikar | 53 | Uncommon | $0.09 |
| Unified WillRise of the Eldrazi · 92 | Rise of the Eldrazi | 92 | Uncommon | $0.17 |
| Uninvited Geist // Unimpeded TrespasserShadows over Innistrad · 94 | Shadows over Innistrad | 94 | Uncommon | $0.09 |
| Unity of PurposeOath of the Gatewatch · 66 | Oath of the Gatewatch | 66 | Uncommon | €0.11 |
| Universal AutomatonModern Horizons 1 Timeshifts · 38 | Modern Horizons 1 Timeshifts | 38 | Uncommon | €0.20 |
| Unleash FuryFoundations Jumpstart · 608 | Foundations Jumpstart | 608 | Uncommon | €0.41 |
| Unleash FuryCore Set 2021 · 170 | Core Set 2021 | 170 | Uncommon | $0.39 |
| Unleash FuryStarter Commander Decks · 166 | Starter Commander Decks | 166 | Uncommon | $0.44 |
| Unlicensed DisintegrationDouble Masters · 224 | Double Masters | 224 | Uncommon | €0.12 |
| Unlicensed DisintegrationKaladesh · 187 | Kaladesh | 187 | Uncommon | $0.18 |
| Unlicensed DisintegrationStarter Commander Decks · 255 | Starter Commander Decks | 255 | Uncommon | €0.13 |
| Unlicensed DisintegrationThe List Tokens · KLD-187 | The List Tokens | KLD-187 | Uncommon | €0.12 |