| Marionette MiteStrike of Neos · 023 | Strike of Neos | 023 | Common | €0.16 |
| Mark of the RoseCrossroads of Chaos · 047 | Crossroads of Chaos | 047 | Ultra Rare | $0.19 |
| Marmiting CaptainSecrets of Eternity · 043 | Secrets of Eternity | 043 | Short Print | $0.18 |
| Marshalling FieldWorld Superstars · 025 | World Superstars | 025 | Prismatic Secret Rare | €0.04 |
| MarshmacaronYu-Gi-Oh! The Dark Side of Dimensions Movie Pack · 013 | Yu-Gi-Oh! The Dark Side of Dimensions Movie Pack | 013 | Ultra Rare | $0.16 |
| MarshmallonPremium Pack (TCG) · 003 | Premium Pack (TCG) | 003 | Secret Rare | €0.17 |
| Marshmallon GlassesPremium Pack (TCG) · 004 | Premium Pack (TCG) | 004 | Secret Rare | €0.15 |
| Marshmao☆YummyDoom of Dimensions · 024 | Doom of Dimensions | 024 | Secret Rare | €19.69 |
| Martial Metal Marcher2018 Mega-Tins · 009 | 2018 Mega-Tins | 009 | Ultra Rare | $0.12 |
| Mart, Knight of the Winter RavenUnlisted Printings | Unlisted Printings | — | — | — |
| Martyr of the Sacred BeastsChaos Origins · 009 | Chaos Origins | 009 | Super Rare | €0.35 |
| MaryokutaiLabyrinth of Nightmare · 076 | Labyrinth of Nightmare | 076 | Common | €0.02 |
| Masaki the Legendary SwordsmanLegend of Blue Eyes White Dragon · 038 | Legend of Blue Eyes White Dragon | 038 | Common | €0.04 |
| Mask ChangeGeneration Force · 097 | Generation Force | 097 | Common | €0.24 |
| Mask Change IIHERO Strike Structure Deck · 019 | HERO Strike Structure Deck | 019 | Common | €0.21 |
| Mask ChargeHERO Strike Structure Deck · 021 | HERO Strike Structure Deck | 021 | Common | €0.31 |
| Masked Beast Des GardiusTactical Evolution: Special Edition · 1 | Tactical Evolution: Special Edition | 1 | Super Rare | €0.10 |
| Masked ChameleonJudgment of the Light · 038 | Judgment of the Light | 038 | Ultra Rare | $0.45 |
| Masked ChopperYu-Gi-Oh! GX Spirit Caller promotional cards · 003 | Yu-Gi-Oh! GX Spirit Caller promotional cards | 003 | Super Rare | €0.34 |
| Masked ClownUnlisted Printings | Unlisted Printings | — | — | — |
| Masked DragonSoul of the Duelist · 026 | Soul of the Duelist | 026 | Common | €0.18 |
| Masked HERO AcidPremium Collection Tin · 018 | Premium Collection Tin | 018 | Secret Rare | $0.45 |
| Masked HERO AnkiPremium Gold: Return of the Bling · 011 | Premium Gold: Return of the Bling | 011 | Gold Secret Rare | $0.31 |
| Masked HERO AtomicMaze of Muertos · 016 | Maze of Muertos | 016 | Super Rare | €0.32 |
| Masked HERO BlastWeekly Shonen Jump October 2016 membership promotional card · 078 | Weekly Shonen Jump October 2016 membership promotional card | 078 | Ultra Rare | €0.15 |
| Masked HERO Dark LawHERO Strike Structure Deck · 044 | HERO Strike Structure Deck | 044 | Super Rare | €0.13 |
| Masked HERO DianPremium Collection Tin · 019 | Premium Collection Tin | 019 | Secret Rare | $0.17 |
| Masked HERO Divine WindHERO Strike Structure Deck · 043 | HERO Strike Structure Deck | 043 | Super Rare | €0.24 |
| Masked HERO Dusk CrowMaze of Muertos · 014 | Maze of Muertos | 014 | Super Rare | €2.57 |
| Masked HERO FountainBattles of Legend: Glorious Gallery · 029 | Battles of Legend: Glorious Gallery | 029 | Secret Rare | €9.00 |
| Masked HERO FurnaceMaze of Muertos · 015 | Maze of Muertos | 015 | Super Rare | €3.82 |
| Masked HERO GokaGeneration Force · 094 | Generation Force | 094 | Rare | $0.12 |
| Masked HERO KogaHERO Strike Structure Deck · 042 | HERO Strike Structure Deck | 042 | Super Rare | €0.26 |
| Masked HERO VaporGeneration Force · 095 | Generation Force | 095 | Super Rare | $0.16 |
| Masked Ninja EbisuOrder of Chaos · 030 | Order of Chaos | 030 | Common | €0.11 |
| Masked SorcererMetal Raiders · 019 | Metal Raiders | 019 | Rare | €0.15 |
| Mask of BrutalityLabyrinth of Nightmare · 020 | Labyrinth of Nightmare | 020 | Rare | €0.16 |
| Mask of DarknessMetal Raiders · 014 | Metal Raiders | 014 | Rare | €0.06 |
| Mask of DispelLabyrinth of Nightmare · 017 | Labyrinth of Nightmare | 017 | Super Rare | €0.24 |
| Mask of RestrictLabyrinth of Nightmare · 018 | Labyrinth of Nightmare | 018 | Ultra Rare | €1.01 |
| Mask of the AccursedLabyrinth of Nightmare · 019 | Labyrinth of Nightmare | 019 | Super Rare | €0.17 |
| Mask of WeaknessLabyrinth of Nightmare · 015 | Labyrinth of Nightmare | 015 | Short Print | €0.04 |
| Masquerade the Blazing DragonBurst of Destiny · 038 | Burst of Destiny | 038 | Ultra Rare | €0.08 |
| Mass DriverMagician's Force · 088 | Magician's Force | 088 | Common | €0.17 |
| Mass HypnosisForce of the Breaker · 058 | Force of the Breaker | 058 | Common | €0.14 |
| MassivemorphRaging Tempest · 080 | Raging Tempest | 080 | Short Print | €0.05 |
| Master Craftsman GamilBattle Pack 3: Monster League · 115 | Battle Pack 3: Monster League | 115 | Common | €0.06 |
| Master & ExpertStarter Deck: Kaiba · 016 | Starter Deck: Kaiba | 016 | Common | €0.14 |
| Masterflare HyperionGhosts From the Past: The 2nd Haunting · 010 | Ghosts From the Past: The 2nd Haunting | 010 | Ultra Rare | €0.28 |
| Master GigDuelist Pack Collection Tin 2009 · 5 | Duelist Pack Collection Tin 2009 | 5 | Super Rare | €0.10 |