| Unchained SyncretismUnlisted Printings | Unlisted Printings | — | — | — |
| Unchained Twins - AruhaChaos Impact · 008 | Chaos Impact | 008 | Rare | €0.76 |
| Unchained Twins - RakeaChaos Impact · 009 | Chaos Impact | 009 | Rare | €0.18 |
| Unchained Twins - SaramaIgnition Assault Special Edition · 4 | Ignition Assault Special Edition | 4 | Super Rare | €0.11 |
| Undaunted Bumpkin BeastBurst of Destiny · 033 | Burst of Destiny | 033 | Common | €0.03 |
| Underclock TakerExtreme Force · 039 | Extreme Force | 039 | Common | €0.07 |
| UnderdogBlazing Vortex · 092 | Blazing Vortex | 092 | Secret Rare | $0.31 |
| Underground ArachnidAbsolute Powerforce · 096 | Absolute Powerforce | 096 | Secret Rare | $0.38 |
| Under PressureSpeed Duel GX: Midterm Paradox · 05 | Speed Duel GX: Midterm Paradox | 05 | Common | $0.04 |
| Underworld CircleMagnificent Monsters · 021 | Magnificent Monsters | 021 | Ultra Rare | €0.02 |
| Underworld Egg ClutchGeneration Force · 068 | Generation Force | 068 | Common | €0.13 |
| Underworld Fighter BalmungJudgment of the Light · 044 | Judgment of the Light | 044 | Rare | $0.21 |
| Underworld Goddess of the Closed WorldBlazing Vortex · 050 | Blazing Vortex | 050 | Secret Rare | $0.30 |
| Underworld Ritual of PredictionDarkwing Blast · 063 | Darkwing Blast | 063 | Common | €0.02 |
| Unending NightmareMaximum Crisis · 079 | Maximum Crisis | 079 | Secret Rare | €0.02 |
| Unexpected DaiCrossed Souls · 065 | Crossed Souls | 065 | Super Rare | €0.17 |
| Unformed VoidNumber Hunters · 049 | Number Hunters | 049 | Super Rare | $0.16 |
| UnibirdDuelist Revolution · 012 | Duelist Revolution | 012 | Super Rare | $0.10 |
| Unicorn BeaconDuelist Revolution · 055 | Duelist Revolution | 055 | Super Rare | $0.28 |
| UnicycularAbsolute Powerforce · 001 | Absolute Powerforce | 001 | Common | €0.11 |
| UnificationAbyss Rising · 079 | Abyss Rising | 079 | Common | €0.10 |
| Unification of the Cubic LordsYu-Gi-Oh! The Dark Side of Dimensions Movie Pack · 045 | Yu-Gi-Oh! The Dark Side of Dimensions Movie Pack | 045 | Ultra Rare | $0.36 |
| Unified FrontThe Dark Illusion · 078 | The Dark Illusion | 078 | Short Print | €0.07 |
| Uniflora, Mystical Beast of the ForestReturn of the Duelist · 031 | Return of the Duelist | 031 | Common | €0.13 |
| UnifrogLight of Destruction · 029 | Light of Destruction | 029 | Common | €0.30 |
| Uni-Horned FamiliarDuelist Revolution · 009 | Duelist Revolution | 009 | Common | €0.11 |
| Union ActivationMaze of the Master · 023 | Maze of the Master | 023 | Ultra Rare | €0.66 |
| Union AttackLight of Destruction · 093 | Light of Destruction | 093 | Super Rare | $0.11 |
| Union CarrierDuel Overload · 009 | Duel Overload | 009 | Ultra Rare | €0.67 |
| Union CombinationSpeed Duel: Battle City Box · 07 | Speed Duel: Battle City Box | 07 | Common | €0.21 |
| Union ControllerMaze of the Master · 022 | Maze of the Master | 022 | Ultra Rare | $0.59 |
| Union DriverEternity Code · 034 | Eternity Code | 034 | Ultra Rare | €0.16 |
| Union HangarStructure Deck: Seto Kaiba · 020 | Structure Deck: Seto Kaiba | 020 | Common | $0.09 |
| Union PilotRage of the Abyss · 022 | Rage of the Abyss | 022 | Common | €0.05 |
| Union RiderMagician's Force · 018 | Magician's Force | 018 | Common | €0.02 |
| Union ScrambleStructure Deck: Seto Kaiba · 030 | Structure Deck: Seto Kaiba | 030 | Common | €0.05 |
| Uni-Song TuningSavage Strike · 066 | Savage Strike | 066 | Common | €0.06 |
| United FrontGeneration Force · 075 | Generation Force | 075 | Rare | €0.05 |
| United ResistanceMagician's Force · 003 | Magician's Force | 003 | Common | €0.02 |
| United We StandLabyrinth of Nightmare · 049 | Labyrinth of Nightmare | 049 | Ultra Rare | €0.02 |
| UnityShonen Jump May 2006 subscription bonus · 006 | Shonen Jump May 2006 subscription bonus | 006 | Ultra Rare | $15.33 |
| Universal AdapterFlames of Destruction Special Edition · 4 | Flames of Destruction Special Edition | 4 | Super Rare | €0.06 |
| Uni-ZombieSecrets of Eternity · 040 | Secrets of Eternity | 040 | Common | €0.23 |
| Unknown SynchronExtreme Victory · 002 | Extreme Victory | 002 | Common | €0.11 |
| Unknown Warrior of FiendStarter Deck: Kaiba · 017 | Starter Deck: Kaiba | 017 | Common | €0.15 |
| Unleash Your Power!Phantom Darkness · 056 | Phantom Darkness | 056 | Common | $0.05 |
| Unlocking the PowerSpeed Duel GX: Duelists of Shadows · 07 | Speed Duel GX: Duelists of Shadows | 07 | Common | $0.10 |
| Unmasked DragonThe New Challengers · 035 | The New Challengers | 035 | Rare | €0.04 |
| UnpossessedSecrets of Eternity · 076 | Secrets of Eternity | 076 | Common | €0.02 |
| Unshaven AnglerSoul of the Duelist · 028 | Soul of the Duelist | 028 | Common | €0.08 |