Frank Heffley

Frank Heffley is Greg's, Rodrick's, and Manny's unpredictable and always-serious father. He is the husband of Susan Heffley (Greg's mom) and the brother of Uncle Joe.

Personality
Frank is over-possessed, disciplinary, argumentative, over-reactive, disciplinary, shrill, irritable, strict, insecure, easily-bothered, ill-tempered, shallow, and emotional. He is constantly bothered and troubled by such small matters, such as Rodrick's typing skills and Greg's silly mistakes, and always wants his sons to look good in front of his boss, a very small matter that Frank constantly gets worked up about; this shows that, like his son, he is shallow and worries about what other people think about him rather than what he thinks about himself. He is very serious and over-possessed in the fact that if his sons do something that irritate him ever so slightly, it makes him become incredibly serious and critical of their behavior. He is a hard worker, and has a poor relationship with all of his sons, since the three cannot relate to each other at all in any way possible, nor can they relate to Frank himself.

Interests
Frank has a strong interest in American history, and this is proven in Rodrick Rules as he builds up a Civil War battlefield in his spare time. He is also interested in working hard at his job, as this is seen recurringly. He does not let anybody into the furnace room where the Civil War battlefield is built, as he is extremely cautious about what he lets people do to his battlefield as he thinks it can be easily ruined.

Dislikes

 * Heavy-metal music - Frank utterly hates this genre of music, since it drives him crazy.
 * Video games - Frank thinks that video games are simply a subject of distraction that prevents Greg from doing exercise.
 * Rowley Jefferson- Frank thinks that Greg's best friend is "accident prone."
 * Teenage delinquents- Frank finds teenage delinquents as a complete source of trouble.
 * His younger brother - Frank finds his brother as a huge troublemaker that always causes some sort of trouble with his family.

Appearance
Greg's illustrations depict Frank wearing a tie, and a few strands of hair falling down in his face. Sometimes, Greg illustrates his father wearing shorts, but this is only when his father goes to bed.

Greg Heffley
Greg and Frank overall have a very poor relationship. In Diary of a Wimpy Kid: The Last Straw, Frank gets fed up with Greg's behavior and threatens to send his son to Spag Union Military Academy to toughen him up, because the academy turned Lenwood Heath, a prankster and delinquent, into a polite person. Greg tries to circumvent this by proving to his dad that he does not deserve this treatment by "doing his best" in soccer and joining the Boy Scouts, among other things, but ultimately fails. It is not until Seth Snella's half-birthday party that Frank realizes that his son's wimpiness is a good characteristic, because it saved himself from looking foolish in front of the entire town. It is in Dog Days where their relationship completely breaks down due to Greg's horseplay getting them in trouble by the police.

Rodrick Heffley
Rodrick and Frank have an extremely poor relationship with one another. Frank is bothered by his poor effort at school, his poor typing skills and most of all, his lack of focus on education, and more focus on heavy-metal music, which Frank utterly hates. According to the second book, Frank would be very happy if Rodrick moved away. In The Last Straw, Frank enrolled Rodrick in a SAT Tuition Class to do better at school, since he becomes fed up with his poor focus, and wants him to look good in front of his boss.

Manny Heffley
Even though Greg assumes that his father spoils Manny as much as he thinks him to do, Frank infact does not spoil Manny, and Frank has no existant relationship with him, since he does not provide Manny by giving him anything in his life, according to the Books.

Susan Heffley
Frank and Susan have a good relationship, though Frank doesn't seem to like some of her traits. For example, he completely doesn't seem to like the fact on how she encourages father-to-son bonding, which Frank finds rather awkward, since most of her plans to show affection with Greg and Rodrick end up disastrous.

Grandpa Heffley
Frank and Grandpa had no distinctive relationship until the fourth book, in which they now have a tense relationship. Frank had a rather minor role in the fourth book until Father's Day, where Grandpa admits that he lied to him about his dog, Nutty, running off to a "butterfly farm", and instead admitted that he accidentally killed his dog. Frank, in response, becomes furious, and decides to buy another dog to make up for the lost one. This dog was named "Sweetheart" much to the three siblings' dismay, or Sweetie for short. Frank becomes obsessed with this dog, even though Sweetie is two times as lazy and repulsive as Greg. In the online book, Frank overreacts to the fact that Grandpa killed his dog even more, and goes as far as to reject his cake and lock him outside their house in the night by himself.

Uncle Joe
Frank has an ongoing rivalry with his younger brother. His younger brother has caused a lot of trouble to Frank's family, such as preventing Manny to go to the toilet. His younger brother is also very immature and never listens to his older brother, as shown in the second book, where Joe claims that Frank's hard-worked Civil War battlefield are mere toys.

Rowley Jefferson
Frank doesn't seem to like Rowley that much. As Greg states, Frank hates him because he finds Rowley "accident prone" because Rowley has caused damage to the Heffleys' property. This results in Frank thinking too deeply about it and coming to the conclusion that Rowley will completely ruin his Civil War battlefield. As such, he does not allow Rowley to go into the basement, where his Civil War battlefield is set.

Trivia

 * Frank's actual profession is not listed so far. Greg, however, does know what his father does for a living. Apparently, it may be hinted that Greg has no intention of telling what he knows.
 * Frank is a junk-food addict, therefore implying that he may have a high cholesterol level.