Henry 'Hank' Rutherford Hill is the main protagonist of King of the Hill. Hank, along with his family (wife Peggy, son Bobby, and niece Luanne), has a central role in most story lines. Hank's voice is provided by series co-creator Mike Judge. The Economist briefly mentioned him as one of the wisest people on television.

Hank Hill, born April 19, stands 6'2" (1.88 meters) in height and his weight has varied throughout the show from 190 lbs to 220 lbs. Among King of the Hill characters, Hank bears one of the more noticeable resemblances to Tom Anderson, a character on Mike Judge's previous animated series, Beavis and Butt-head. The similarities in both voice and (to a slightly lesser extent) physical appearance between Hill and Anderson are especially noticeable when comparing early King of the Hill episodes to "Beavis and Butthead"'s final episodes or movie. Hank also inherited much of Tom's serious, conservative personality; the differences, however, reflect the differences in tone between the two series. Unlike Tom, a senior citizen whose grumpiness was typically as absurd as his antagonists' stupidity, Hank's humorously no-nonsense attitude makes him a sympathetic voice of reason within the series. He also expresses a love of propane, similarly to Anderson's admiration of butane which ironically Hank sees as an inferior gas. Hank is known to threaten people who have ticked him off with him saying " I'm gonna kick your ass." Hank drives a red Ford Ranger (1997-2000), a red Ford F-250 Super Duty (2001-2008) and a red Ford F-350 (2009-2010).