Manny Heffley is Greg's younger brother appearing in Diary of a Wimpy Kid. He is black hair and black eyes. His main outfit is composed of: a green short sleeved shirt, a white diaper and wears no shoes. He is voiced by Kath Soucie. At his age, he is 6 years old. At his romantic dance with Brianna, his outfit is composed of: a tuxedo that his brother wears.
- Susan Heffley (Mother)
- Frank Heffley (Father)
- Greg Heffley (Older Brother)
- Rodrick Heffley (Oldest Brother)
- Brianna Maxwell (Love Interest)