Collin Lee is Greg's backup friend. In Dog Days, Greg was banned from seeing Rowley for the rest of the summer after "burning" him. So he told Rowley to tell his parents he was going to Collin's house, but secretly going to go camping at the Game Hut for a Twisted Wizards tournament. In The Ugly Truth, Collin appears briefly during the Lock-In when they were playing ice breakers. Collin is played by Alex Ferris in the movie.
- In the online book, Collin bears a strong resemblance to Alex Aruda. He takes up much of Rowley’s significant roles, such as when Rodrick was tutoring Greg and Rowley how to play the drums, and is also Greg’s backup friend.
- However, in the book series, Collin is short with curly hair and no glasses. He also has an extremely minor role, being only mentioned a few times and shown once.
- In Diary of a Wimpy Kid Online, he was the one who got his house toilet-papered. However in the first book, Gramma's house was toilet-papered.
- His online version resembles Alex Aruda.