Harry Potter is a series of seven books written by J.K. Rowling, Harry Potter first appeared in the late nineties and quickly changed the children's book market. Pottermore is the digital publishing, e-commerce, entertainment, and news company from J. K. Rowling and is a global digital publisher of Harry Potter and the Wizarding World.
Magic Tree House is an American series of children's books written by American author Mary Pope Osborne.
Magic School Bus is a series of children's books about science, written by Joanna Cole and illustrated by Bruce Degen.
Diary of a Wimpy Kid is a series of fiction books written by the American author and cartoonist Jeff Kinney. All the main books are the journals of the main character, Greg Heffley.
The Nancy Drew Mystery Stories is the long-running "main" Nancy Drew series, published between 1930 and 2003, under the pen name Carolyn Keene.
T
he Hardy Boys series are mystery-adventure books depicting brothers Frank and Joe's daring capers. Like the Nancy Drew series, the characters were created by Edward Stratemeyer for his book packaging company Stratemeyer Syndicate and were all ghost written under the pen name Franklin W. Dixon.
Dork Diaries is a humorous children's book series written and illustrated by Rachel Renée Russell. The series, written in a diary format, uses drawings, doodles, and comic strips to chronicle the daily life of its 14-year-old protagonist, Nikki Maxwell, in and outside of middle school.
The World According to Humphrey series is written by Betty Birney and features a lovable hamster named Humphrey.
Spirit Animals is a series written by multiple authors in the world of Erdas, where every child who comes of age must discover if they have a spirit animal. Other series also include Spirit Animals Fall of the Beasts.
Fancy Nancy is a children's series written by Jane O'Connor. Nancy is a young girl who loves to be fancy! Fancy does not mean expensive or luxurious for Nancy. It simply means busy, embellished, colorful, or French.
Children of the Red King is a series of children fantasy school and adventure novels written by British author Jenny Nimmo, first published by Egmont 2002 to 2009. It is sometimes called "the Charlie Bone series" after its main character.
Amelia Bedelia is the protagonist and title character of a series of American children's books written by Peggy Parish until her death in 1988, and by her nephew, Herman Parish, beginning in 1995.
The American Girl series, by various authors, is a collection of novels set within toy line's fictional universe. Since its inception, American Girl has published books based on the dolls, with novels and other media to tie in with their dolls.
Dear America is a series of historical fiction novels for older girls published by Scholastic in 1996. The series was canceled in 2004 with its final release, Hear My Sorrow. However, it was relaunched in the fall of 2010.
The Adventures of the Bailey School Kids is a best-selling children's book chapter book series. The books in the series are co-authored by Marcia T. Jones and Debbie Dadey.
The Haunted Library series is written by Edgar Award Winner Dori Hillestad Butler, The Haunted Library is a not-too-scary chapter book mystery series that follows the adventures of Claire and her ghost friend, Kaz.
Judy Moody is a series of children's books by Megan Jo McDonald which concern a third grade girl named Judy.
A Series of Unfortunate Events is a series of thirteen children's novels by Lemony Snicket, the pen name of American author Daniel Handler.
Cupcake Diaries by Coco Simon is a tween series features a group of four unique girls who form a cupcake club as a way to navigate through the wild terrain that is middle school.
Diadem is a series of fantasy novels by John Peel. The series takes place on several different worlds, collectively referred to as the Diadem.
Amber Brown is a series of realistic fiction novellas for children created and originally written by Paula Danziger; later written by Elizabeth Levy and Bruce Coville.
Goosebumps is a series of children's horror fiction novellas by American author R. L. Stine.
Septimus Heap is a series of fantasy novels featuring a protagonist of the same name written by English author Angie Sage.
Artemis Fowl is a series of eight science fiction fantasy novels written by Irish author Eoin Colfer, featuring the criminal mastermind Artemis Fowl II. Eoin Colfer also writes the W.A.R.P series.
Serafina is a newer series (2015) written by Robert Beatty about a brave girl that secretly lives in the basement of the grand Biltmore Estate.
The Chronicles of Narnia is a series of seven fantasy novels by C. S. Lewis.
Warriors is a series of novels published by HarperCollins; it is written by authors Kate Cary, Cherith Baldry, Tui Sutherland, with the plot developed by editor Victoria Holmes, who collectively use the pseudonym Erin Hunter. 
Other series by 'this' author are Warriors: Dawn of the Clans, Warriors: the New Prophecy, Warriors: Power of Three, Warriors: Omen of the Stars, Warriors: A Vision of Shadows, Seekers, Seekers: Return to the Wild, Survivors, Survivors: The Gathering Darkness, and Bravelands.
The Big Nate book series by Lincoln Pierce, based on the Big Nate comic strip, chronicles the small and large dramas of life in the sixth grade with humor and style.
The Kingdom Keepers is a series of children's novels written by American author Ridley Pearson.
Bad Kitty is a series of American children's books by Nick Bruel, about a housecat named Kitty, who often wreaks havoc about her owner's home.
Theodore Boone has spent more time in the courtroom than almost anywhere else, and there's always a new adventure waiting. Theo happily dispenses legal advice to friends and community members, just like real lawyers. Written by John Grisham.
The Just Grace series is a written by Cherise Mericle Harper and third-grader Grace Stewart, who gets stuck with the name “Just Grace” when she tries to distinguish herself from the three other Graces in her class.
Who Was? Series by a multitude of author with over 150 titles published by Penguin Random House. This series tells the incredible stories of trailblazers, legends, innovators, and creators.
Cam Jansen is a fifth grade sleuth with the photographic memory—who solves the case with the help of her best friend, Eric; written by David Adler.
The Boxcar Children is a classic children's literary franchise originally created and written by the American first-grade school teacher Gertrude Chandler Warner.
In the small California town of Santa Vista, four eight-year-old best friends help found and maintain The Critter Club, a rescue shelter set on saving “lost and lonely” animals, in this sweet and silly chapter book series.
Little House on the Prairie is a series of American children's novels written by Laura Ingalls Wilder based on her childhood in the Great Plains during the 1800s.
Hank the Cowdog is a long running, ongoing series of children's books written by John R. Erickson and illustrated by Gerald L. Holmes.
The 39 Clues is a series of adventure novels written by a collaboration of authors, including Rick Riordan, Gordon Korman, Peter Lerangis, Jude Watson, Patrick Carman, Linda Sue Park, Margaret Peterson and more.
Sew Zoey is a series written by Chloe Taylor that follows the double life of Zoey Webber as a quirky middle school outcast who also has an inventive Sew Zoey fashion design blog that puts her on the A-list at Fashion Week in this adorable middle grade series!
Redwall is a series of children's fantasy novels by Brian Jacques.
The Mallory McDonald series is a children's series written by Laurie Friedman.
Capital Mysteries is a series of mystery novels for young readers written by Ron Roy.
The I Survived series is written by Lauren Tarshis and tells a terrifying and thrilling story from history, through the eyes of a kid who lived to tell the tale.
Captain Underpants is a children's novel series by American author and illustrator Dav Pilkey.