Santa Claus is a historical character who is said to bring presents to all the nice children in the world. In Cabin Fever, Santa is mainly mentioned and Greg thinks about how he looks after kids if they're doing bad things. After Jared Pyle, a bad kid got a dirt bike for Christmas, Greg started thinking if the list is even accurate.
- Santa is mentioned in the book series (except Cabin Fever) and appears briefly in the Diary of a Wimpy Kid (2010 film) adaptation.
- Santa Claus are real life people.