Dumb Jock

Exactly What It Says On the Tin.

A jock isn't always a jerk. Sometimes he is instead (or as well) Book Dumb (at best) or is Too Dumb to Live at worst. Much like his girlfriend, The Cheerleader of the Brainless Beauty variety, he's more concerned with his image then school work. If he's not a jerk it might be because he's too dumb to realize he's supposed to be (though the Jerk Jock can also be incredibly stupid like the caveman mentality of the Dumb Muscle). Often times the better he is at his respective sport, the dumber the jock is like a Genius Ditz and the more valued he is by his team and the facility who will make sure that he maintains his position regardless of his apparent mental incompetence.

While The Cheerleader can easily be dumb, the word jock refers to a player of rather aggressive sports, primarily football.

This belief likely stems from the idea that high school and college athletes are too busy training to do homework and that talented athletes are given special treatment by the school system so they don't need to study. Or perhaps because the physically-intimidating bully is more likely to turn to sports then the stereotypical nerd. Or it could simply be the concept of Competitive Balance being applied to real life.

Can overlap with Popular Is Dumb, Jerk Jock, and is the spear counterpart to the Brainless Beauty type of The Cheerleader. Always Male because a girl is more likely to be somewhere between the Girl Next Door to a Lesbian Jock who, while tough is mentally competent.

The inversion is Academic Athlete.

Anime and Manga

 * Eyeshield 21's Otawara is the embodiment of this trope. The guy's so dumb he forgets to wear pants on a daily basis, but got a sports scholarship at Ojou by being one of the fastest and strongest nose guards in High School Football.
 * To a (slightly) lesser extent there's Taki of Deimon, Kamagaruma of Taiyou, Homer of Nasa, and Achilles of Teikoku.
 * Slam Dunk: Four of the five starting players for Shohoku are of the Book Dumb variety. Ironic considering that until that year Shohoku's basketball players were known for their respectable grades (of course until that year they had been a rather terrible team).
 * Miyagi, Sakuragi, and Mitsui in particular are known as the "Dumbass Trio".

Comic Books

 * Moose from Archie Comics fits this trope to a T.
 * One of Captain Haddock's many, many technically-insults is "complete athlete!", meaning someone who practices many different sports suffers in his intellectual development.

Film

 * The Blind Side is an example of the teachers helping Michael Oher pass his classes so he can play football.

Literature

 * Harry of The Dresden Files believes Hendricks, Gentleman Johnny Marcone's primary enforcer, to be one of these. He fits all the stereotypes: large, no neck, close cropped hair cut, speaks mainly in grunts and intimidating glares, and used to play football in high school. However, it's later revealed that he's actually quite intelligent, just The Stoic, and is at one point seen working on his Master's thesis.

Live Action TV

 * Glee has football players Finn and Puck, but is inverted with Mike, who is a straight-A student.
 * There is an episode of Sabrina the Teenage Witch where Sabrina writes an article for the school paper exposing the preferential treatment given to school athletes and gets the star pitcher for the baseball team benched until he finishes his assignments. She goes to help him and he has doodled that he hates her and wrote her names with three "n"s.

Video Games

 * Gary in Escape From St Maryshas trouble remembering the injuries he experienced just minutes ago, among other intellectual shortcomings.

Western Animation

 * Dash and Han from Danny Phantom.
 * Defied in an episode of King of the Hill, where a star high school football is given a pass on all his classes just so he can play; it's taken as a given that he couldn't pass the classes on his own merits. He doesn't realize that this is happening though, and once he finds out he tries to succeed on his own.
 * Daria's Kevin Thompson is easily a finalist for the dumbest living organism in Lawndale. While not a bully, he's a little narcissistic, dumb as a box of rocks, wears his uniform everywhere, and is in general bad at everything that isn't football. At least he's sweet to his head Cheerleader girlfriend, Brittany, genuinely friendly to his teammates, and amicable towards everyone else, even the unpopulars.