- Movie Madness
- Movie Mayhem
- Movie Menace
- Movie Mission
- Moxie and the Art of Rule Breaking
- Mr Dog and a Hedge Called Hog
- Mr Dog and the Rabbit Habit
- Mr Dog and the Seal Deal
- Mr Dog Animal Adventures: Volume 2
- Mr. Chickee's Funny Money
- Mr. Chickee's Messy Mission
- Mr. Lemoncello and the Titanium Ticket
- Mr. Lemoncello's Very First Game
- Mr. Pin: The Chocolate Files
- Ms. Carolyn
- Mudshark
- Mummy's Revenge
- Mummy's Tomb
- Murder at the Mall
- Murder at the Museum
- Murder Fit for a King
- Murder Mysteries 5: The Scent of Blood
- Murder Mysteries 6: Certain Death
- Murder Mysteries 7: Poison Pen
- Murder Mysteries 8: Love Him to Death
- Murder Mysteries 9: Blood Hound
- Murder on Mars
- Murder on the Safari Star
- Murder on the Set
- Museum Mayhem
- Museum Mystery Squad and the Case of the Curious Coins
- Museum Mystery Squad and the Case of the Hidden Hieroglyphics
- Museum Mystery Squad and the Case of the Moving Mammoth
- Museum Mystery Squad and the Case of the Moving Mammoth
- Museum Mystery Squad and the Case of the Roman Riddle
- Museum Mystery Squad and the Case of the Vanishing Viking
- Museum Mystery Squad Books 1 to 3
- Mutant Mantis Lunch Ladies!
- Muumion arvoitus. Lasse-Maijan etsivätoimisto
- MVP #1: The Gold Medal Mess
- MVP #2: The Soccer Surprise
- MVP #3: The Football Fumble
- MVP #4: The Basketball Blowout
- My Best Friend Is a Secret Agent
- My Brother the Duck
- My Dad, the Private Eye
- My Teacher The Ghost
- My Thoughts Exactly, By Darcy Diggins, Middle School BioSPYchologist
- Mysteries in Our National Parks: Cliff-Hanger
- Mysteries in Our National Parks: Deadly Waters
- Mysteries In Our National Parks: Ghost Horses
- Mysteries in Our National Parks: The Hunted
- Mysteries in Our National Parks: Wolf Stalker
- Mysteries of Sherlock Holmes
- Mysteriet på "Oceanic"
- Mysterium. Der schwarze Drache
- Mystery & Mayhem
- Mystery at Blue Ridge Cemetery
- Mystery at Kittiwake Bay
- Mystery at Magnolia Mansion
- Mystery at Malachite Mansion
- Mystery at Moorsea Manor
- Mystery At Pirate's Cove
- Mystery at Plymouth Rock
- Mystery at Shildii Rock
- Mystery at the Christmas Market
- Mystery Club: A Graphic Novel (Mr. Wolf's Class #2)
- The Mystery in Arizona: Trixie Belden
- Mystery in the Jackson House
- Mystery Island
- Mystery Map
- Mystery of the Ballerina Ghost
- Mystery of the Bewitched Bookmobile
- Mystery of the Dark Tower
- Mystery of the Disappearing Dolphin
- Mystery of the Golden Temple
- Mystery of the Island Jewels
- Mystery of the Lazy Loggerhead - Brazil 2
- Mystery of the Melting Snowman
- Mystery of the Midnight Rider
- Mystery of the Min Min Lights
- Mystery of the Phantom Heist
- Mystery of the Pink Owl Flu
- Mystery of the Secret Room
- Mystery of the Skull
- Mystery of the Thief in the Night
- Mystery of the Troubled Toucan
- Mystery of the Turtle Snatcher
- Mystery on Magnolia Circle
- Mystery on Maui
- Mystery on the Mayhem Express
- Mystery on the Menu
- Mystery Seekers Club
- Mystère chez l'antiquaire
- Mystère en croisière
- Mystères et détectives
- Mystères sur les rails - Le vol du Highland Falcon - Tome 1 - Roman dès 9 ans