The best middle grade book is almost always the start of a long series. Tween readers don't want a single story to end — they want six more books, then a spin-off, then a companion guide. Here are the middle grade series with the deepest backlists, the most loyal fans, and the highest re-read rates. Browse every middle grade series in our catalog or start your tween on one of these.
Percy Jackson and the Olympians by Rick Riordan
The series that made Greek mythology feel cool again. Twelve-year-old Percy discovers he's the son of Poseidon and gets pulled into a world of quests, monsters, and demigod camp drama. Five books in the original series, then the whole connected Riordan universe — Heroes of Olympus, Trials of Apollo, Kane Chronicles, Magnus Chase. Once a tween falls in, they have years of reading ahead.
📖 Browse the Percy Jackson reading order → · 📖 Complete reading order guide → · 📚 Find The Lightning Thief on Amazon →
Harry Potter by J.K. Rowling
Books 1–4 are middle grade in scope and tone; books 5–7 mature into upper middle grade and YA. Still the gold standard for the magical-school fantasy genre, and still pulling new tween readers in every year.
📖 Browse the Harry Potter reading order → · 📖 Complete reading order guide → · 📚 Find Sorcerer's Stone on Amazon →
Wings of Fire by Tui T. Sutherland
Five young dragons are prophesied to end a generations-long war between the queens of three SandWing sisters. Found family, palace intrigue, distinct dragon clans, and an active fandom that ranks "which tribe are you?" with the same energy other kids put into Harry Potter houses. The graphic novel adaptations are pulling reluctant readers into the world.
📖 Browse the Wings of Fire reading order → · 📖 Complete reading order guide → · 📚 Find The Dragonet Prophecy on Amazon →
Diary of a Wimpy Kid by Jeff Kinney
Greg Heffley's middle school disasters, told through cartoon-illustrated diary entries. Nearly twenty books in the main series and counting, plus the Rowley Jefferson companion series and a hit movie/animated franchise. Possibly the single best series for transforming a reluctant reader into a devoted one.
📖 Browse the Diary of a Wimpy Kid reading order → · 📚 Find Diary of a Wimpy Kid on Amazon →
Ava & Carol Detective Agency by Thomas Lockhaven
Twelve-year-old best friends Ava and Carol have a knack for stumbling into real mysteries — diamond smugglers at a museum, a kidnapped show dog, a haunted mansion, an ancient ring with a dangerous secret. Lockhaven writes them in the spirit of Nancy Drew and the Boxcar Children but with modern kid-detective tools — coding, deciphering, tech smarts. The first book, The Mystery of the Pharaoh's Diamonds, won a Mom's Choice Award.
📖 Browse the full Ava & Carol reading order → · 📚 Find The Mystery of the Pharaoh's Diamonds on Amazon →
Keeper of the Lost Cities by Shannon Messenger
Twelve-year-old Sophie discovers she's an elf and gets pulled into the Lost Cities to learn about her real heritage. The series has grown into a deep, lore-rich world with a devoted fan base that rivals Harry Potter for sheer enthusiasm — readers tear through the chunky books and immediately ask when the next one comes out.
📖 Browse the Keeper of the Lost Cities reading order → · 📚 Find Keeper of the Lost Cities on Amazon →
The Mysterious Benedict Society by Trenton Lee Stewart
Four gifted children are recruited for a secret mission inside a sinister boarding school. Each kid has a specific cognitive strength, and the team dynamic is what carries the series. Logic puzzles, ciphers, and real friendship. There's also a Disney+ adaptation that captures the spirit of the books well.
📖 Browse the MBS reading order → · 📚 Find The Mysterious Benedict Society on Amazon →
Magic Tree House by Mary Pope Osborne
Jack and Annie find a magic tree house full of books, and every book they touch transports them to a different time and place. The main series spans ancient Egypt to dinosaurs to the moon, with the Merlin Missions sub-series, Fact Tracker companions, and now graphic novel adaptations bringing the total well over a hundred volumes. The gateway series for kids transitioning from chapter books into middle grade.
📖 Browse the full Magic Tree House reading order → · 📚 Find Dinosaurs Before Dark on Amazon →
Quest Chasers by Thomas Lockhaven and Grace Lockhaven
Eevie, Tommy, and Drew get pulled into Equis — a hidden magical world ruled by an evil queen with an unquenchable thirst for human souls — and have to solve deadly puzzles to survive. A fantasy adventure trilogy that blends magic with mystery-style puzzle-solving in a way that's rare in middle grade. Three books: The Deadly Cavern, The Screaming Mummy, and The Chalice of Souls.
📖 Browse the Quest Chasers reading order → · 📚 Find The Deadly Cavern on Amazon →
How to pick a starter series
If your tween loves: Action and humor → Percy Jackson or Wimpy Kid. Magic and chosen ones → Harry Potter or Keeper of the Lost Cities. Animal characters → Wings of Fire. Solving puzzles → Mysterious Benedict Society or Quest Chasers. Detective stories → Ava & Carol Detective Agency. History adventures → Magic Tree House.
The best part of middle grade is the depth. Once your tween finds the world they want to live in, they have months — sometimes years — of reading ahead.
📚 Browse every middle grade series in our catalog, or explore all our reading guides.