The film focuses on the intrigue inside Excelsior Union High School. Michael J. Fox plays J.J. Manners, who becomes enamored with Beth Franklin (Nancy McKeon), the girlfriend of Beau Middleton (Edwards), the class president and quarterback. Middleton is also the richest student, a spoiled young man who drives around in a brand-new convertible. The core story involves Manners and Middleton competing for the affections of Beth. Ultimately this rivalry culminates in a drag race between the two. The result of the race tips the balance and changes the face of the dynamics within the school irrevocably. In the end, J.J. ends up winning Beth's affections.
High School USA provides examples of:
- Black and Nerdy: Otto Lipton, the school's resident genius. He has built a robot that accompanies him everywhere.
- Car Meets House: When J.J.'s crew are preparing to modify J.J.'s car, they are waiting for Crazy Leo to arrive with a big engine. Leo arrives by driving a bus through the wall of the warehouse.
- Cock Fight: The main plot involves an escalating war between J.J. and Beau as they fight for Beth's affections. It culminates in a Compete for the Maiden's Hand drag race.
- Compete for the Maiden's Hand: J.J. and Beau have a drag race to compete for the right to date Beth.
- Empty Fridge, Empty Life: Otto invites JJ over for dinner, but JJ declines, saying he has plenty of food. Cue Otto looking in JJ's fridge and seeing only a bottle of ketchup
- High School: As indicated by the title.
- Honey Trap: Beau sends a pair of girls to seduce Archie and Chuckie and trick them into wrecking the Firebird.
- Pants-Pulling Prank: A pair of girls are determined to get a photo of the butt of the Big Man on Campus Beau Middleton. One attempt involves trying to pull down his pants in the haunted house at the school fair. However, they accidentally pull down the pants of the fat nerd and photograph his butt. At the end of the movie, Beau gets pantsed by a robot (It Makes Sense in Context) and the girls get their photo.
- The Precious, Precious Car: Archie's dad's Pontiac Firebird. When Beau finds out that J.J. is planning to use the car in the drag race, he sends a couple of girls round to seduce Archie and Chuckie into taking them for a ride in it, and then causing them to crash the car by distracting them. The kids then concoct a scheme to persuade Archie's dad that he wrecked the car himself.
- Protagonist-Centered Morality: J.J. Manners is portrayed as the everyman good guy while the preppy Beau Middleton gets the bad guy treatment. J.J. isn't entirely innocent. He crashes Beau's party and hits on Beau's girlfriend constantly, even kissing her in public, and in the sight of Beau, yet J.J. is still supposed to be the good guy.
- Robot Buddy: Otto is accompanied everywhere by his personal robot. It obeys any instruction prefixed by the word "Robot".
- The Schlub Pub Seduction Deduction: Archie and Chuckie realise that the two beautiful girls who urge them to take Archie's dad's car out for a ride were sent by Beau Middleton after the bimbos have caused them to wreck The Precious, Precious Car.
- Smart People Build Robots: Otto Lipton is a genius who has created a robot that he believes to be capable of going into space, and which accompanies him everywhere.
- Tin-Can Robot: Otto's robot. Of course, it was built by an amateur in his basement, so the design can be expected to be a little crude.
- Watch the Paint Job: Archie's dad's Pontiac Firebird. When Beau finds out that J.J. is planning to use the car in the drag race, he sends a couple of girls round to seduce Archie and Chuckie into taking them for a ride in it, and then causing them to crash the car by distracting them.
- What a Piece of Junk: After the Firebird is wrecked, J.J. and his Ragtag Bunch of Misfits attempt to salvage the drag race by transforming J.J.'s crappy old car into something with a chance of winning. They do so by installing a bus engine in it, giving it a great power to weight ratio.