Diary of a Wimpy Kid: Christmas (2025) follows Greg Heffley as he prepares for what he hopes will be the perfect holiday, only to face one disaster after another. The story begins in early December when Greg becomes obsessed with getting the newest gaming console being released right before Christmas. Convinced that this year will finally go his way, he creates an elaborate plan to prove to his parents that he deserves it. However, his attempts to look responsible quickly unravel as his grades slip and his behavior draws unwanted attention.

At school, the annual “Winter Fun Fair” is announced, and Greg sees it as his chance to earn extra credit and impress his parents. Unfortunately, Rowley immediately volunteers them both for the most embarrassing job: wearing giant snowman costumes and handing out tickets. Greg tries to switch roles with someone else, but his efforts only cause more chaos, including a disastrous incident involving a runaway sled that destroys part of the fair’s decorations. Greg’s humiliation grows, and Rowley’s cheerful optimism somehow makes everything worse.

Back at home, the Heffley family attempts to create a simple, peaceful holiday season, but nothing goes as planned. Manny becomes obsessed with capturing Santa on video, Rodrick keeps sabotaging the decorations, and their parents decide that all gifts this year will be “practical.” Greg panics, convinced he is losing any chance of getting the console. Desperate, he decides to secretly enter a neighborhood Christmas contest with a large cash prize that he hopes to use for the gift.

Greg ropes Rowley into helping him create the most over-the-top holiday display in the neighborhood. Their decorations include giant inflatable characters, excessive lights, and a mechanical reindeer that constantly malfunctions. The chaos leads to several neighborhood complaints, and their final attempt blows a fuse that knocks out power on their entire street. Greg is banned from the contest and grounded, convinced Christmas is officially ruined.

As Christmas approaches, Greg reflects on how his plans always go wrong. Surprisingly, Rowley shows up with a handmade coupon book filled with small gifts, reminding Greg of what friendship means. Touched, Greg realizes that maybe Christmas isn’t about the biggest presents. When he finally wakes up on Christmas morning, he finds that his parents, despite everything, managed to get him the console after all.

The film ends with the Heffleys enjoying a chaotic but heartfelt Christmas together, while Greg admits in his diary that even though nothing went according to plan, this might have been the best holiday yet.