|Name||Grandpa Heffley (first name unknown)|
|Online Appearance?||Yes (as Pappy Heffley)|
|“||There you go!||”|
—Grandpa says as he fills Greg's plate with watercress salad, thinking Greg likes it.
Grandpa Heffley is the lovable but clueless grandfather of Greg, Rodrick and Manny, the father of Frank Heffley, Joe Heffley and Gary Heffley, the father-in-law of Susan Heffley and the widower of Nana Heffley.
In Cabin Fever, he appears only in a photo, but he makes a younger appearance when his son, Frank told him about his bully, Billy Staples he came to Billy's house along with his wife, telling Mr. Staples about Billy's actions.
In Hard Luck, Greg mentioned that Grandpa had a girlfriend because, at Leisure Towers, a lot of women lined up at Grandpa's door trying to win him over with casseroles and baked goods.
Later, in Old School, he left the nursing home after they raised the rent and moved in with Greg's family. He stole Greg's room when Susan told him he could sleep wherever he wanted and began driving Frank insane. When the Heffelys left to visit Rodrick at his job, he invited a bunch of single women over to party. Grandpa tries to make an excuse, but Frank doesn't buy it and puts Grandpa in a time out (apparently, it was awkward to punish your own father). Frank then has his sons watch over Grandpa so he doesn't do anything stupid again. He later dated a widow named Darlene, who broke up with him.
He is seen briefly at the dinner table in Double Down.
Grandpa is strange, critical, unpredictable, and quite ignorant at times. He means well and seems pretty jovial and kind, however. He sets his TV only on the CCTV channel, which he enjoys watching, infuriating Greg as he cannot watch any "real" television shows at his grandpa's retirement home. He makes a dish called watercress salad, which is an uncooked salad with vinegar and green beans. Greg and Rodrick think it is disgusting; their grandpa seems to not care. He loves to play a game called Gutbusters as well, and forces Greg and Rodrick to play; Greg always wins because his Grandpa thinks the nonsensical jokes are funny and he also beats Rodrick because he laughs on purpose because he keeps his mouth filled with milk when Greg's turn comes. In The Ugly Truth, it is revealed that he smoked when no one is looking. He might have been told on by Greg, as he has never been seen smoking since. In Old School, he said he accidentally invited all women from his dating site when he tried to invite only one to watch a movie.
Grandpa is always seen with his spectacles, but he takes them off when sleeping. He also wears dentures, has a large nose, is short and overweight, wears old fashioned clothes and suspenders. He is half bald with only some hair.
- Diary of a Wimpy Kid Online (First appearance)
- Diary of a Wimpy Kid: Rodrick Rules (First book appearance)
- Diary of a Wimpy Kid: Rodrick Rules (film)
- Diary of a Wimpy Kid: Dog Days
- Diary of a Wimpy Kid: Dog Days (film)
- Diary of a Wimpy Kid: The Ugly Truth
- Diary of a Wimpy Kid: Cabin Fever
- Diary of a Wimpy Kid Do-It-Yourself Book
- The Wimpy Kid Do-It-Yourself Book
- The Wimpy Kid Movie Diary
- Diary of a Wimpy Kid: Hard Luck
- Diary of a Wimpy Kid: Old School
- Diary of a Wimpy Kid: Double Down
- Wimpy Wonderland
- Diary of an Awesome Friendly Kid (Indirectly Mentioned)
- Greg is his favorite grandson.
- According to Greg's family tree in the extended version of The Wimpy Kid Do-It-Yourself Book, Grandpa's parents are Remus and Lulu Heffley, and Gammie is the mother of Greg's other grandfather, on Susan's side. However, when she later appeared in the Ugly Truth, Gammie was instead said to be on Frank's side of the family, meaning she is either Grandpa or Nana's mother.
- It's unknown if he's still living with Greg's family because he's not seen or mentioned in the twelfth and thirteen books. It's possible that he's was able to move into a different retirement home that had cheaper rent, as it was briefly mentioned in book-10 that the family was looking for a cheaper nursing home. It's also possible that he passed away.
- He does not wear glasses in the movie.