| Title | Code | Date | Publisher | System (Setting) |
|---|
 M.U T-Shirt | CHA9302 | | Chaosium | None |
| M.U. Mug | CHA9304 | | Chaosium | None |
 Macabre Tales | SG-MT1 | 2011 | Spectrum Games | Macabre Tales |
 Machina Arcana * | | 2014 | MAGE Company | Machina Arcana |
| Machina Arcana: Core Dice | | 2019 | Adreama Games | Machina Arcana |
| Machina Arcana: Game Mats | | 2019 | Adreama Games | Machina Arcana |
| Machina Arcana: Player Boards | | 2014 | MAGE Company | Machina Arcana |
| Machinations Through Time * | AHC62 | 2021 | Fantasy Flight Games | Arkham Horror: The Card Game |
 The Machine King | cr3006 | 2014 | Cthulhu Reborn | Call of Cthulhu (Gaslight) |
| Machine Tractor Station Kharkov-37 | CHA0310 | 2004 | Chaosium | Call of Cthulhu (Classic) |
| Macho Women With Guns * | | 1988 | Blacksburg Tactical Research Center | Macho Women With Guns |
| Macho Women With Guns * | | 1994 | Blacksburg Tactical Research Center | Macho Women With Guns |
 Mad Cthulhu | CHN5en | 2014 | Chimerae Hobby Group | Mad Cthulhu |
| Mad Love | | 2018 | Imp House | Mad Love |
| The Mad Man's Auction | | Jan 2024 | Chaosium | Call of Cthulhu (Classic) |
| The Mad Priest | | Dec 2019 | Chaosium | Call of Cthulhu (Strange Aeons) [Viking] |
| Mad Sci: How to Train Your Shoggoth | | Feb 2024 | Chaosium | Call of Cthulhu (Now) |
| Madmen | | 2013 | Reality Blurs | tremulus |
| Madness and Desire | | 2017 | Self Published | Madness and Desire |
| Madness and Mayhem * | GSP02004 | 2015 | Game Soapbox Productions | Madness and Mayhem |
| Madness at Midnight | MIB1018 | 2017 | Mr B Games | Madness at Midnight |
| Madness of McGuffin | PGC008 | 2018 | Pleasant Company Games | Ancient Terrible Things |
| Madness on the Orient Express * | CHA6057 | 2014 | Chaosium | Call of Cthulhu (Classic) |
| Madness Stirs | | 2019 | Kolossal Games | All Manor of Evil |
| Madness: The Solo Version | | 2011 | Self Published | Madness: The Solo Version |
| Magic of the Old West * | | 2021 | Skirmisher Publishing | Call of Cthulhu (Darker Trails) |
| Magical Charms in Cthulhu Invictus | | 2019 | Golden Goblin Press | Call of Cthulhu (Invictus) |
| Mail-Order Bribe | | Jul 2022 | Chaosium | Call of Cthulhu (Classic) |
| The Major | | 2011 | Self Published | CthulhuTech |
| The Makhonjwa Egg | MUH0090312 | Jul 2023 | Modiphius Entertainment | Achtung! Cthulhu |
 Making Movies | 1 | 1987 | Self Published | Call of Cthulhu (Classic) |
| The Malevolent Grove | MUH0010323 | 2022 | Modiphius Entertainment | Achtung! Cthulhu |
| The Malignity | | Mar 2020 | Chaosium | Call of Cthulhu (Classic) |
| Mall Rats | | May 2020 | Chaosium | Call of Cthulhu (Now) |
| Malleus Monstrorum | CHA23102 | 2007 | Chaosium | Call of Cthulhu (Classic) |
 Malleus Monstrorum Deck | CHA23171 | 2021 | Chaosium | Call of Cthulhu (Classic) |
| Malleus Monstrorum Slipcase Set * | CHA23170-X | 2020 | Chaosium | Call of Cthulhu (Classic) |
| Malleus Monstrorum Volume 1: Monsters of the Mythos | CHA23168 | 2020 | Chaosium | Call of Cthulhu (Classic) |
| Malleus Monstrorum Volume 2: Deities of the Mythos | CHA23169 | 2020 | Chaosium | Call of Cthulhu (Classic) |
| Malum Umbra | CHA0353 | 2008 | Chaosium | Call of Cthulhu (Invictus) |
| The Man at the Foot of the Bed | | 2022 | Gallant Knight Games | Tiny Cthulhu |
| The Man Downstairs | | Feb 2018 | Chaosium | Call of Cthulhu (Classic) |
 The Mana Bros | | | Self Published | Call of Cthulhu (Classic) |
| Manic Depressive | 1 | 1985 | Self Published | Call of Cthulhu (Classic) |
| Manoeuvres on the Moor | | Apr 2021 | Chaosium | Call of Cthulhu (Now) |
| Manos: The Fingers of Fate | | Oct 2021 | Chaosium | Call of Cthulhu (Strange Aeons) [1969] |
| Mansions of Madness * | CHA2327 | 1990 | Chaosium | Call of Cthulhu (Classic) |
| Mansions of Madness * | CHA23110 | 2007 | Chaosium | Call of Cthulhu (Classic) |
| Mansions of Madness * | MAD01 | 2011 | Fantasy Flight Games | Mansions of Madness |
| Mansions of Madness * | MAD20 | 2016 | Fantasy Flight Games | Mansions of Madness |
| Mansions of Madness Poster | CHA9307 | | Chaosium | None |
| Mansions of Madness Volume 1: Behind Closed Doors | CHA23167 | 2020 | Chaosium | Call of Cthulhu (Classic) |
| Mansions of Madness: Dice Pack | MAD24 | 2017 | Fantasy Flight Games | Mansions of Madness |
| Manumbalik | | Jul 2023 | Chaosium | Call of Cthulhu (Now) |
| The Many Deaths of Edward Bigsby | | 2014 | Innsmouth House Press | Trail of Cthulhu |
| The Many Deaths of Edward Bigsby | PELGT42 | 2016 | Pelgrane Press | Trail of Cthulhu |
| Many Fires | PELGT25 | 2011 | Pelgrane Press | Trail of Cthulhu |
| Maps for a Mad Scientist's Lair | | Jul 2022 | Chaosium | Call of Cthulhu (Classic) |
| Maps for Blank | | Mar 2022 | Chaosium | Call of Cthulhu (Classic) |
| Maps for Burning Stars | | Nov 2021 | Chaosium | Call of Cthulhu (Classic) |
| Maps for Curio | | Dec 2022 | Chaosium | Call of Cthulhu (Classic) |
| Maps for Dissonance | | Nov 2021 | Chaosium | Call of Cthulhu (Classic) |
| Maps for Genius Loci * | | Sep 2021 | Chaosium | Call of Cthulhu (Classic) |
| Maps for Terror in Tangier | | Dec 2021 | Chaosium | Call of Cthulhu (Classic) |
| Maps for The Darkness Beneath the Hill | | Apr 2021 | Chaosium | Call of Cthulhu (Classic) |
| Maps for The Haunting (The Corbitt House) | | Dec 2021 | Chaosium | Call of Cthulhu (Classic) |
| Maps for The Lightless Beacon | | Aug 2021 | Chaosium | Call of Cthulhu (Classic) |
| The Mark of Evil * | | | Stygian Fox | Call of Cthulhu (Classic) |
 The Mark of Madness | CT66 | 2015 | Fantasy Flight Games | Call of Cthulhu LCG |
| Mark of the Beast * | CHA6062 | 2016 | Chaosium | Call of Cthulhu (Classic) |
| The Mask | | Apr 2022 | Chaosium | Call of Cthulhu (Now) |
| The Mask of the Black Sun | | Mar 2024 | Chaosium | Call of Cthulhu (Classic) |
| Masks of Nyarlathotep * | CHA2307-X | 1984 | Chaosium | Call of Cthulhu (Classic) |
| Masks of Nyarlathotep * | CHA3304 | 1989 | Chaosium | Call of Cthulhu (Classic) |
| Masks of Nyarlathotep | | 2005 | Fantasy Flight Games | Call of Cthulhu CCG |
| Masks of Nyarlathotep * | CHA23118 | 2010 | Chaosium | Call of Cthulhu (Classic) |
| Masks of Nyarlathotep * | CHA23153 | 2018 | Chaosium | Call of Cthulhu (Classic) |
| Masks of Nyarlathotep | EH09 | 2018 | Fantasy Flight Games | Eldritch Horror |
| Masks of Nyarlathotep | CW-U10 | 2019 | Petersen Games | Cthulhu Wars |
| The Masks of Nyarlathotep Companion (Limited) | 60-MONC-08 | 2016 | Sixtystone Press | Call of Cthulhu (Classic) |
| The Masks of Nyarlathotep Companion (Unlimited) | 60-MONC-03 (?) | 2016 | Sixtystone Press | Call of Cthulhu (Classic) |
| Masks of Nyarlathotep Conversion Notes | | 2008 | Self Published | Trail of Cthulhu |
| Masks of Nyarlathotep Gamer Prop Set * | | 2018 | The H P Lovecraft Historical Society | Call of Cthulhu (Classic) |
| Masks of Nyarlathotep Poster | CHA9306 | | Chaosium | None |
| Masks of the Mythos | SCI012 | 2022 | Onyx Path Publishing | Scion |
| Mason Mansion | | Oct 2022 | Chaosium | Call of Cthulhu (Classic) |
| Massacre in the Woods | | Jun 2024 | Chaosium | Call of Cthulhu (WWII) |
| The Master of Convicts | cr3005o | 2019 | Cthulhu Reborn | Call of Cthulhu (Convicts) |
| Mauerfall 1961-1989 | | Feb 2020 | Chaosium | Call of Cthulhu (Now) |
| The Maze of Madness | | 2004 | Self Published | Call of Cthulhu (Classic) |
| Mean 13 | | 2021 | Self Published | Chthonian Highways |
| Mechanika | | 2014 | Xaos Publishing | Mechanika |
| Medical Forms | | Jan 2018 | Chaosium | Call of Cthulhu (Classic) |
| The Medicine Show * | | Jul 2018 | Chaosium | Call of Cthulhu (Classic) |
| Mellified Monsters | | Jul 2021 | Last Mile Game Logistics | Call of Cthulhu (Classic) |
| Memorable Major Wounds | | May 2023 | Chaosium | Call of Cthulhu (Classic) |
| The Memories Below | | Jan 2024 | Chaosium | Call of Cthulhu (Now) |
| Menace From the Moon | CHA0336 | 2007 | Chaosium | Call of Cthulhu (Classic) |
| Meridian | APU8167 | 2024 | Arc Dream Publishing | Delta Green |
| Message in a Bottle | PELGY16D | 2023 | Pelgrane Press | The Yellow King |
| Mi-Go | MIS5045 | | Misfit Studios | Mutants and Masterminds |
| Mi-Go | | 2018 | Self Published | Sundered Epoch: Generations |
| Mi-Go Mind Switch Promo Card | | Apr 2008 | Steve Jackson Games | Munchkin |
| The Mi-Go Outpost Inside of the Red Mesa | | 2017 | Self Published | None |
| Michigan Mythos: Fall Colors | | Aug 2021 | Chaosium | Call of Cthulhu (Classic) |
| Midgard and Mythos | KP-Warlock-5E-1-Mythos | 2018 | Kobold Press | Pathfinder |
| Midnight Harvest | OWC4003 | 2008 | Super Genius | Call of Cthulhu (Now) |
| Midnight Harvest | OWC4008E | 2011 | Super Genius | Savage Worlds (Realms of Cthulhu) |
| A Midsummer Night's Darkness | | Dec 2023 | Chaosium | Call of Cthulhu (Strange Aeons) [1900s] |
| A Midsummer Night's Haunting | | 2013 | Self Published | Cthulhu Dark |
| Mike's Free Mythos Maps Collection | | Mar 2018 | Chaosium | Call of Cthulhu (Classic) |
| Millan's Tomb | | Oct 2024 | Chaosium | Call of Cthulhu (Classic) |
| The Million Flavoured Ones | | May 2024 | Chaosium | Call of Cthulhu (Now) |
| Mind Over Matter | | 2016 | Self Published | Call of Cthulhu (Classic) |
| Mingled Remains | | Mar 2024 | Chaosium | Call of Cthulhu (Classic) |
| Mini Cthulhu | | 2018 | SchilMil Games | AuZtralia |
| Minions | CHA2365 | 1997 | Chaosium | Call of Cthulhu (Classic) |
| Minions of Cthulhu | | 2011 | Self Published | Minions of Cthulhu |
| The Mirror Collection | | Aug 2021 | Chaosium | Call of Cthulhu (Now) |
| The Misery Archive | cr3005mis | 2021 | Cthulhu Reborn | Call of Cthulhu (Convicts) |
| Misfits and Menaces: Tricks and Treats | MIS5016 | 2008 | Misfit Studios | Mutants and Masterminds |
| The Miskatonic | | 2018 | Self Published | JumpChain! |
| Miskatonic Country Scenarios: A Keeper's Guide | SHP-MC-1 | 2020 | Sentinel Hill Press | Call of Cthulhu (Classic) |
| The Miskatonic Five | | Jul 2021 | Chaosium | Call of Cthulhu (Strange Aeons) [1970] |
| Miskatonic Horror Expansion | VA70 | 2011 | Fantasy Flight Games | Arkham Horror |
| Miskatonic Madness | | 2005 | Self Published | Miskatonic Madness |
| The Miskatonic Museum * | AHC03 | 2017 | Fantasy Flight Games | Arkham Horror: The Card Game |
| Miskatonic School for Boys | | 2016 | Fun to 11 | Miskatonic School for Boys |
| Miskatonic School for Girls | F2110001 | 2012 | Fun to 11 | Miskatonic School for Girls |
| Miskatonic Shoreside Conservatory | | 2022 | Symphony Entertainment | Cthulhu Dark |
| Miskatonic Tales | | 2022 | Self Published | Miskatonic Tales |
| Miskatonic Tales: Journey to Innsmouth | | 2025 | Chaosium | Miskatonic Tales: Journey to Innsmouth |
| Miskatonic Tunnels | | 2019 | Micro RPG | One Page Cthulhu |
| Miskatonic U. Doctoral Diploma | CHA5101-D | 1987 | Chaosium | Call of Cthulhu (Classic) |
| Miskatonic U. Graduate Kit | CHA5101 | 1987 | Chaosium | Call of Cthulhu (Classic) |
| Miskatonic U. Master of Arts Diploma | CHA5101-M | 1987 | Chaosium | Call of Cthulhu (Classic) |
| Miskatonic University | CHA2352 | 1995 | Chaosium | Call of Cthulhu (Classic) |
| Miskatonic University | CHA2389 | 2005 | Chaosium | Call of Cthulhu (Classic) |
| Miskatonic University Antarctic Expedition Pack | CHA2381 | 1999 | Chaosium | Call of Cthulhu (Classic) |
| Miskatonic University Forms | | Jan 2018 | Chaosium | Call of Cthulhu (Classic) |
| Miskatonic University Honorary Degree Promo Card | | Oct 2012 | Steve Jackson Games | Munchkin |
| Miskatonic University: The Restricted Collection | | 2019 | Chaosium | Mikatonic University: The Restricted Collection |
| Missed Dues * | CHA0419 | 2013 | Chaosium | Call of Cthulhu (Classic) |
| Missed Dues and Other Adventures * | | 2013 | Chaosium | Call of Cthulhu (Classic) |
| The Missing Cat | | Sep 2024 | Chaosium | Call of Cthulhu (Now) |
| The Missing Fossil | | Aug 2024 | Chaosium | Call of Cthulhu (Classic) |
| Missing in the Rocky Mountains | | Jul 2024 | Chaosium | Call of Cthulhu (Classic) |
| Missing in the Woods | | Jan 2021 | Chaosium | Call of Cthulhu (Now) |
| The Missing of Dunver Island | | Aug 2024 | Chaosium | Call of Cthulhu (Classic) |
| The Mist Sower | | Jul 2021 | Chaosium | Call of Cthulhu (Classic) |
| Mists of the Aeons | | | Self Published | Call of Cthulhu (Classic), Call of Cthulhu (Delta Green) |
| Mizuumi no bakemono * | | Aug 2018 | Chaosium | Call of Cthulhu (Now) |
| Modern Days NPCs Art Pack | | Aug 2022 | Chaosium | Call of Cthulhu (Now) |
 Modiphia | 2 | Sum 2017 | Modiphius Entertainment | Call of Cthulhu (Achtung!) |
| Modiphia | 3 | Win 2017 | Modiphius Entertainment | Call of Cthulhu (Achtung!) |
| Modiphia | 4 | Win 2020 | Modiphius Entertainment | Achtung! Cthulhu |
| Modiphia | 5 | Spr 2021 | Modiphius Entertainment | Achtung! Cthulhu |
| Mom's Coming to Dinner 1: Hot Merchandise | WDF23410 | 2014 | WildFire Games | CthulhuTech |
| Mom's Coming to Dinner 2: Hot Merchandise II | WDF23411 | 2014 | WildFire Games | CthulhuTech |
| Mom's Coming to Dinner 3: New Parents | WDF23412 | 2014 | WildFire Games | CthulhuTech |
| Mom's Coming to Dinner 4: Finding the Fallen | WDF23413 | 2014 | WildFire Games | CthulhuTech |
| A Moment of Your Time | | 2016 | Self Published | Lovecraftesque |
| Monophobia | 1001 | 2010 | Unbound Publishing | Call of Cthulhu (Classic) |
| Monophobia - Rules Light Solo Roleplaying | | Aug 2020 | Chaosium | Call of Cthulhu (Classic) |
| Monopoly: Cthulhu | USOMN056414 | 2016 | The Op | Monopoly |
| Monsieur Deloffre Has Gone Quite Mad! | | Feb 2024 | Chaosium | Call of Cthulhu (Regency) |
| Monster Pack Cthulhu | IEL 51350 | 2017 | IELLO | King of ? |
| Monsters of the Mythos | | 2012 | Self Published | Yellow Dawn |
| Monsters Vs Heroes: Volume 2 - Cthulhu Mythos | ARCG007 | 2019 | Ares Games | Monsters Vs Heroes |
| Monstrous Heritage Promo Card | | Aug 2010 | Steve Jackson Games | Munchkin |
| Monstrous Perversions | 2 | | Self Published | Call of Cthulhu (Classic) |
| Monstrous Perversions | 1 | 1985 | Self Published | Call of Cthulhu (Classic) |
| Moonglow | | Dec 2018 | Chaosium | Call of Cthulhu (Strange Aeons) [Future] |
| Moonlight Made Madness | | 2021 | Librarians and Leviathans | Call of Cthulhu (Strange Aeons) [Bronze Age] |
| More Adventures in Arkham Country | MRP0007 | 2010 | Miskatonic River Press | Call of Cthulhu (Classic) |
| More Excuses to Kill Things | | 1995 | Blacksburg Tactical Research Center | Macho Women With Guns |
| More Tales of Terror | PAG2105 | 2000 | Pagan Publishing | Call of Cthulhu (Classic) |
| More Zombies | | 2015 | Devil Pig Games | Shadows Over Normandie |
| Morsels of Madness | | 2020 | Squamous Studios | Feed the Shoggoth! |
| Mortal Coils | PAG1007 | 1998 | Pagan Publishing | Call of Cthulhu (Classic) |
| The Mortal Muncher | | Oct 2024 | Chaosium | Call of Cthulhu (Classic) |
| Mortal Remains | WDF23002 | 2009 | WildFire Games | CthulhuTech |
| A Most Awful Plant | | 1999 | Self Published | Call of Cthulhu (Now) |
| Mother's Love | JCG029 | 2019 | Just Crunch Games | The Cthulhu Hack |
| Mouldering Gramrye of Mythos Spells | | Nov 2020 | Chaosium | Call of Cthulhu (Classic) |
| The Mound in the Yard | | Oct 2020 | Self Published | GURPS (Horror), Call of Cthulhu (Now) |
| Mount Katahdin's Shadow | | Aug 2024 | Chaosium | Call of Cthulhu (Now) |
| Mountains of Chaos | | 2023 | Godot Games | Among Cultists |
| The Mountains of Madness | CT16 | 2008 | Fantasy Flight Games | Call of Cthulhu LCG |
| Mountains of Madness | EH03 | 2014 | Fantasy Flight Games | Eldritch Horror |
| Mountains of Madness | 51374 | 2017 | IELLO | Mountains of Madness |
| The Moving Star | | Sep 2021 | Chaosium | Call of Cthulhu (Cyberpunk) |
| Muerte al Chupacabras! * | SKP01010 | 2010 | Skirmisher Publishing | Call of Cthulhu (Classic) |
 Multiverse | 3 | Sum 1984 | Adventure Simulations | Call of Cthulhu (Classic) |
| The Mummy of Pemberley Grange | | Sep 2020 | Chaosium | Call of Cthulhu (Classic) |
| Munchkin Board of Health | SJG5577 | 2014 | Steve Jackson Games | Munchkin |
| Munchkin Booster 2012 * | SJG4237 | 2012 | Steve Jackson Games | Munchkin |
| Munchkin Booster 2013 * | SJG4240 | 2013 | Steve Jackson Games | Munchkin |
| Munchkin Booster 2014 * | SJG4245 | 2014 | Steve Jackson Games | Munchkin |
| Munchkin Cthulhu | SJG1447 | 2007 | Steve Jackson Games | Munchkin |
| Munchkin Cthulhu Blank Cards | SJG1448 | | Steve Jackson Games | [None Listed] |
| Munchkin Cthulhu Cursed Demo | SJG1456 | 2008 | Steve Jackson Games | Munchkin |
| Munchkin Cthulhu Guest Artist Edition | SJG1516 | 2016 | Steve Jackson Games | Munchkin |
| Munchkin Cthulhu Kill-O-Meter | SJG5540 | 2012 | Steve Jackson Games | Munchkin |
| Munchkin Cthulhu Sanity Check | SJG4267 | 2019 | Steve Jackson Games | Munchkin |
| Munchkin Dungeon: Cthulhu! | MKD003 | 2020 | Steve Jackson Games | Munchkin |
| Munchkin Hidden Treasures * | SJG1507 | 2015 | Steve Jackson Games | Munchkin |
| A Murder at Heck's Peak | | Jul 2022 | Chaosium | Call of Cthulhu (Darker Trails) |
| Murder at Miskatonic * | SKP0820 | 2008 | Skirmisher Publishing | Call of Cthulhu (Classic) |
| Murder at the Excelsior Hotel * | AHC38 | 2019 | Fantasy Flight Games | Arkham Horror: The Card Game |
| Murder Incorporated * | | 2003 | Self Published | Call of Cthulhu (Classic) |
| Murder of Crows | OWC4001 | 2008 | Super Genius | Call of Cthulhu (Classic) |
| The Murderer of Thomas Fell | | 2008 | Pelgrane Press | Trail of Cthulhu |
| The Murderer of Thomas Fell | | 2014 | Pelgrane Press | Call of Cthulhu (Classic) |
| Murmurs of Evil | CT35 | 2010 | Fantasy Flight Games | Call of Cthulhu LCG |
| The Museum | | 2014 | Reality Blurs | tremulus |
| Music From a Darkened Room | | 2005 | Self Published | Call of Cthulhu (Delta Green) |
| Music From a Darkened Room | APU8112 | 2017 | Arc Dream Publishing | Delta Green |
| The Music of Erich Zann | | 2019 | Man O'Kent Games | The Music of Erich Zann |
| Music Recital | | 2018 | Sixpence Games | Cultists of Cthulhu |
| Muskateers vs Cthulhu | WFG-MVC-001 | May 2024 | Nightfall Games | Call of Cthulhu (Strange Aeons) [1620s] |
| Muskateers vs Cthulhu Keeper Pack | WFG-MVC-002 | May 2024 | Nightfall Games | Call of Cthulhu (Strange Aeons) [1620s] |
| Mutable Deceptions Vol 1: Jazz Age Newspapers | cr7001 | 2013 | Cthulhu Reborn | Call of Cthulhu (Classic), Trail of Cthulhu |
| My Aunt's House | | 1996 | Self Published | Call of Cthulhu (Classic) |
| My Guardian Monster | | Jul 2019 | Chaosium | Call of Cthulhu (Now) |
| My Little Cthulhu Promo Card | | Mar 2009 | Steve Jackson Games | Munchkin |
| My Little Sister Wants You to Suffer | | Dec 2022 | Chaosium | Call of Cthulhu (End Time) |
| My Overcrowded Pineal Gland | | 2000 | Self Published | Call of Cthulhu (Classic) |
| My Uncle's Trunk | | Dec 2022 | Chaosium | Call of Cthulhu (Now) |
| Mysteria Matris Oblitae | | 2008 | Arc Dream Publishing | Call of Cthulhu (Classic) |
| Mysteries of Hungary | CHA0340 | 2007 | Chaosium | Call of Cthulhu (Gaslight), Call of Cthulhu (Now), Call of Cthulhu (Classic) |
| Mysteries of Ireland | CHA0408 | 2012 | Chaosium | Call of Cthulhu (Classic) |
| The Mysteries of Mesoamerica | PAG1012 | 2009 | Pagan Publishing | Call of Cthulhu (Classic) |
| Mysteries of Morocco | CHA0306 | 2004 | Chaosium | Call of Cthulhu (Classic) |
| Mysteries of Sudan | CHA0362 | 2009 | Chaosium | Call of Cthulhu (Gaslight) |
| Mysteries of the Manor | MUH0010353 | Oct 2023 | Modiphius Entertainment | Achtung! Cthulhu |
| Mysteries of the Raj | CHA0391 | 2010 | Chaosium | Call of Cthulhu (Gaslight) |
| Mysteries of the Worm * | CHA6037 | 2009 | Chaosium | Call of Cthulhu (Classic) |
| Mysteries of Tibet | CHA0351 | 2008 | Chaosium | Call of Cthulhu (Classic) |
| The Mystery at Oak Harbour | | Sep 2021 | Chaosium | Call of Cthulhu (Classic) |
| Mystery Box | | Jun 2024 | Chaosium | Call of Cthulhu (Classic) |
| Mystery Card | | 2017 | Ninja Star Games | Arkham Ritual |
| The Mystery of April Snow | GGP | 2020 | Golden Goblin Press | Call of Cthulhu (Classic) |
| The Mystery of Shirdley Hall | | 2012 | Cakebread and Walton | Clockwork and Chivalry |
| Mystery of the South Channel Pilot Light | | Aug 2022 | Chaosium | Call of Cthulhu (Classic) |
| Mystery on Mona | | 2008 | Self Published | Call of Cthulhu (Invictus) |
| Mystic Alliances | CHA0363 | 2009 | Chaosium | Call of Cthulhu (Now) |
| Mythic Legends | 8-BIT-ATTACK-2 | 2020 | Petersen Games | 8-Bit Attack |
| Mythos | LG041MY06 | 2013 | Legendary Games | Pathfinder |
| Mythos * | | 2017 | Paranoid Miniatures | Mythos Board Game |
| Mythos * | MTH99001 | 2020 | Warcradle Studios | Mythos Board Game |
| Mythos Artifacts | | Mar 2022 | Chaosium | Call of Cthulhu (Classic) |
| Mythos Case Files: Fungi Mine | SG0007 | 2013 | Solace Games | Call of Cthulhu (Now) |
| The Mythos Dossiers | CB71204 | 2012 | Cubicle 7 | Call of Cthulhu (Laundry) |
| Mythos Encounters | | 2021 | Diceless Hero Games | Mythos Encounters |
| Mythos Expeditions | PELGT37 | 2014 | Pelgrane Press | Trail of Cthulhu |
| Mythos Horror Creation System | | 2017 | Avalon Games | None |
| Mythos in Medias Res | | 2016 | Xipe Totec Press | Cthulhu Confidential, Cthulhu Dark, Trail of Cthulhu, Delta Green, Call of Cthulhu (Classic) |
| Mythos Magic | CHA0341 | 2007 | Chaosium | Call of Cthulhu (Classic) |
| Mythos Magic | | 2019 | Kobold Press | Dungeons and Dragons |
| The Mythos Merchant | | Mar 2021 | Chaosium | Call of Cthulhu (Classic) |
| Mythos Miniatures | | 2008 | Island of Wak Wak | Mythos Miniatures |
| Mythos Mishaps | | 2020 | Tales By Bob | Mythos Mishaps |
| Mythos Monster Silhouettes Art Pack | | Dec 2017 | Chaosium | Call of Cthulhu (Classic) |
| Mythos Monster Tokens Sample Pack | | Mar 2023 | Chaosium | Call of Cthulhu (Classic) |
| Mythos Monsters | MIS7066 | 2017 | Misfit Studios | Savage Worlds |
| Mythos Monsters | | 2018 | Self Published | None |
| Mythos Monsters | LGP454HO045E | 2021 | Legendary Games | Dungeons and Dragons |
| Mythos Monsters * | LGP454HO04PF | 2022 | Legendary Games | Pathfinder |
| Mythos Monsters * | LGP454HO04PF2 | 2022 | Legendary Games | Pathfinder |
| Mythos Monsters | LGP454HO04BFR | 2024 | Legendary Games | Black Flag |
| Mythos Monsters 2 | | 2021 | Self Published | None |
| Mythos Mysteries | | 2021 | Dapper Fish Designs | Grey Cells |
| Mythos Mystic Connection | RGGSLEM0027 | 2018 | Rogue Genius Games | Pathfinder (Starfinder) |
| The Mythos Society Guide to New England | SKPE1423 | 2014 | Skirmisher Publishing | Call of Cthulhu (Classic) |
| Mythos Tales | MT001 | 2013 | At the Table Games | Mythos Tales |
| Mythos Tales * | | 2016 | 8th Summit | Mythos Tales |
| Mythos Tales * | | 2018 | Grey Fox Games | Mythos Tales |
| Mythos Too | LG102MY29 | 2014 | Legendary Games | Pathfinder |
| Mythos World | MW001 | 2015 | Diceless Hero Games | Mythos World |
| Mythos World Basic Moves | | 2015 | Diceless Hero Games | Mythos World |
| Mythos World Playbooks | | 2015 | Diceless Hero Games | Mythos World |
| Mythos World Resources Volume 1 | MW111 | 2018 | Diceless Hero Games | Mythos World |
| Mythosophobia | | 2016 | Xipe Totec Press | Trail of Cthulhu, Delta Green, Cthulhu Confidential, Call of Cthulhu (Classic) |
| Mythoturbation | | 2016 | Xipe Totec Press | Delta Green, Call of Cthulhu (Now), Cthulhu Dark, Trail of Cthulhu |