Diary of a Wimpy Kid: Party Pooper is the 20th book in the Diary of a Wimpy Kid book series written and illustrated by Jeff Kinney. The sequel to Hot Mess, the book was unveiled on February 27, 2025.^[1] It will be released on October 21, 2025.^{[citation needed]}

The plot centers around Greg Heffley expecting a surprise birthday party which doesn't happen. Even worse, his whole family has forgotten it was his birthday. After the disappointing incident goes viral, his parents are Facebook-shamed, and guilted into throwing him a "blowout" party which Greg plans to maximize for presents.^[1]