Fight or Flight (Diary of a Wimpy Kid, Book 21)

Release date October 20, 2026

Greg Heffley is about to learn that surviving middle school is no easy feat.

In Fight or Flight, the 21st book in Jeff Kinney’s globally bestselling Diary of a Wimpy Kid series, Greg's hard-earned expertise on navigating the rough-and-tumble world of middle school is put to the test.

When a secret binder filled with Greg’s notes on the school’s biggest bullies falls into the wrong hands, his world quickly begins to unravel. Now it’s a race against time before the truth comes out. Will Greg throw in the towel—or go down swinging?

A hilarious read for kids ages 8-12, packed with classic Wimpy Kid humor, unforgettable middle-school drama, friendship twists, and Jeff Kinney's signature illustrations.