Johnny Joestar is an American former jockey turned paraplegic, and is the main protagonist of Part 7. He is a depressive man with a bleak outlook on life, but he is also very stubborn and capable of extreme, unwavering determination to the point of disregarding any risks or consequences, putting his goal above all else. He joins the Steel Ball Run race to find out the secret behind Gyro Zeppeli's steel balls, as Johnny believes they're capable of healing his legs. Johnny was once a horse racing prodigy. However, when waiting in line for a play, the girl he was with convinced him to cut to the front of the line and bribe the bouncers to throw out the youth in the front of the line, who had been waiting there all night. Furious, the youth shot Johnny in the back, paralyzing him from the waist down.

Spoiler

Johnny earns a Stand named "Tusk" when they venture into the Devil's Palm as a result of their fight with Dio and Dr. Ferdinand. Tusk is able to fire Johnny's spinning fingernails similar to a revolver, with the nails having to take a few seconds to regrow. This long range attack becomes his primary means of defense. His Stand is small in size and has the same star-pattern over it as on Johnny's clothing, it appears to reside inside of him and only comes out to offer advice. It cannot speak, only make animal-like noises. Later in the series, Johnny masters Gyro's "Spin" technique and uses it with his Stand's fingernail bullets; at one time, even being able to use it on himself. His Stand also evolves although remaining similar in appearance, now able to fire from the toenails on Johnny's paralyzed feet.