- Mild
- Words like hell and damn are frequently used
- The majority of the language typically comes from Hank, he constantly uses phrases such as "Jack Ass", "Im gonna kick your ass" and "Got dangit".
- There is some toilet humour throughout the series. This includes talk of constipation, fart jokes/noises, comments about dog poop, Bobby peeing his pants in fright, characters getting diarrhea after drinking tainted beer, and Bobby having diarrhea after eating stolen lutefisk at a religious meet-and-greet.
- Some milder expletives and name-calling, including "pig", "jerk", "commie", "redneck", "hillbilly", "boobies", "old coot", "banana" (used as a racial slur), "brat", "fatty" and "moron", among others.
- Bobby uses the word "slut" in Season 1. "Thieving slut" is also said by an old man in a mid-season storyline.
- Since there is nothing severely profane, many parents might pass King of the Hill as a family program, even if they might want to supervise their children while watching.
- Throughout the course of the show, there has only two uses of "goddamn".
- Contains only infrequent use of mild coarse language such as "son of a bitch", "pissed", and "crap". Also contains infrequent use of very mild coarse language such as "ass", "dammit", "hell", and "bastard".