| Undergrowth StadiumCommander Masters · 435 | Commander Masters | 435 | Rare | $7.43 |
| Undergrowth StadiumCommander Masters · 620 | Commander Masters | 620 | Rare | €13.78 |
| Undergrowth StadiumCommander Masters · 666 | Commander Masters | 666 | Rare | €10.53 |
| Undergrowth StadiumCommander Legends · 714 | Commander Legends | 714 | Rare | €13.42 |
| Undergrowth StadiumTeenage Mutant Ninja Turtles Eternal · 80 | Teenage Mutant Ninja Turtles Eternal | 80 | Rare | €4.12 |
| Undergrowth StadiumMagic Online Promos · 85950 | Magic Online Promos | 85950 | Rare | — |
| Undergrowth Stadium // Undergrowth StadiumCommander Masters Art Series · 49 | Commander Masters Art Series | 49 | — | — |
| Underhanded DesignsKaladesh · 104 | Kaladesh | 104 | Uncommon | €0.18 |
| Underhanded DesignsKaladesh Remastered · 108 | Kaladesh Remastered | 108 | Uncommon | — |
| UndermineDuel Decks: Ajani vs. Nicol Bolas · 62 | Duel Decks: Ajani vs. Nicol Bolas | 62 | Rare | €3.55 |
| UndermineInvasion · 282 | Invasion | 282 | Rare | €4.13 |
| UndermineStarter Commander Decks · 254 | Starter Commander Decks | 254 | Rare | $1.83 |
| UndermineWorld Championship Decks 2001 Tokens · ar282 | World Championship Decks 2001 Tokens | ar282 | Rare | €2.15 |
| Undermountain AdventurerCommander Legends: Battle for Baldur's Gate · 260 | Commander Legends: Battle for Baldur's Gate | 260 | Rare | $0.35 |
| Undermountain AdventurerCommander Legends: Battle for Baldur's Gate · 594 | Commander Legends: Battle for Baldur's Gate | 594 | Rare | $0.37 |
| Undermountain AdventurerBattle for Baldur's Gate Promos · 260s | Battle for Baldur's Gate Promos | 260s | Rare | €1.24 |
| Underrealm LichRavnica: Clue Edition · 215 | Ravnica: Clue Edition | 215 | Mythic Rare | €6.80 |
| Underrealm LichGuilds of Ravnica · 211 | Guilds of Ravnica | 211 | Mythic Rare | €6.34 |
| Underrealm LichGuilds of Ravnica Promos · 211p | Guilds of Ravnica Promos | 211p | Mythic Rare | €5.52 |
| Underrealm LichGuilds of Ravnica Promos · 211s | Guilds of Ravnica Promos | 211s | Mythic Rare | €5.92 |
| Undersea InvaderKaldheim · 78 | Kaldheim | 78 | Common | €0.05 |
| 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 |
| UndertakerTime Spiral Timeshifted · 53 | Time Spiral Timeshifted | 53 | Special | €0.23 |
| Under the SeaJumpstart Front Cards · 40 | Jumpstart Front Cards | 40 | — | — |
| 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 |
| UnderwaterAvatar: The Last Airbender Jumpstart Front Cards · 17 | Avatar: The Last Airbender Jumpstart Front Cards | 17 | — | — |
| Underwater Tunnel // Slimy AquariumDuskmourn: House of Horror · 79 | Duskmourn: House of Horror | 79 | Common | €0.12 |
| Underworld BreachMystery Booster 2 Tokens · 200 | Mystery Booster 2 Tokens | 200 | Rare | €6.83 |
| Underworld BreachTheros Beyond Death Promos · 161p | Theros Beyond Death Promos | 161p | Rare | €6.63 |
| Underworld BreachTheros Beyond Death Promos · 161s | Theros Beyond Death Promos | 161s | Rare | €17.08 |
| Underworld BreachTeenage Mutant Ninja Turtles Source Material · 10 | Teenage Mutant Ninja Turtles Source Material | 10 | Mythic Rare | $7.11 |
| Underworld BreachSpecial Guests · 9 | Special Guests | 9 | Rare | €17.83 |
| Underworld BreachTheros Beyond Death · 161 | Theros Beyond Death | 161 | Rare | €7.43 |
| Underworld BreachTheros Beyond Death · 324 | Theros Beyond Death | 324 | Rare | €11.10 |
| Underworld BreachSecret Lair Drop Tokens · 2040 | Secret Lair Drop Tokens | 2040 | Rare | €26.53 |
| Underworld BreachSecret Lair Drop Tokens · 2045 | Secret Lair Drop Tokens | 2045 | Rare | $82.07 |
| Underworld BreachMagic Online Promos · 79977 | Magic Online Promos | 79977 | Rare | — |
| Underworld CerberusTheros · 208 | Theros | 208 | Mythic Rare | €0.28 |
| Underworld ChargerTheros Beyond Death · 120 | Theros Beyond Death | 120 | Common | $0.08 |
| 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 ConnectionsCommander 2015 · 138 | Commander 2015 | 138 | Rare | €0.20 |
| Underworld ConnectionsCommander 2017 · 128 | Commander 2017 | 128 | Rare | €0.40 |
| Underworld ConnectionsDuel Decks: Jace vs. Vraska · 73 | Duel Decks: Jace vs. Vraska | 73 | Rare | $0.32 |