Johnny Joestar (ジョニィ・ジョースター Joni Jōsutā), born Jonathan Joestar (ジョナサン・ジョースター Jonasan Jōsutā), is the main protagonist of the seventh part of the JoJo's Bizarre Adventure series, Steel Ball Run, and the seventh JoJo of the series. He also appears as a posthumous character in JoJolion.
A former jockey turned paraplegic, Johnny joins the SBR race to find out the secret behind Gyro Zeppeli's Steel Balls as they're the only thing capable of healing his legs. Over the course of the race, Johnny becomes both a Spin User and a Stand User when he acquires Tusk.
Johnny is a young man of below-average height and slim to medium build. He has light eyes, and light, shoulder-length hair curling upwards at its ends.
Johnny always wears a knit cap, printed with many small five-pointed stars. His hair sticks out of holes on either side of the top, taking a shape like short horns. A horseshoe hangs from the front; framing an image of the dark silhouette of the profile of a horse's reared head.
Johnny wears similarly star-patterned pants; of a piece with footwear bearing spurs. He commonly wears a light-colored, hooded, short-sleeved top; printed with thick lines in the approximate form of a harness (later, with patches in the shape of hearts adorning both shoulders). A long feather (bordered by black with one black spot at its tip) emerges from under the back of his collar, and he wears wrist cuffs patterned with Stars and Stripes.
As a child, Johnny wears a long-sleeved blue top with stars on them, a light blue coat tied round the waist as well as light brown trousers and blue boots.
In cold weather, Johnny wears a longer-sleeved top of a similar design. His collar is outlined with fur, and he keeps several feathers at his back.
As a paraplegic, before the beginning of the race he is seen using a wheelchair; but during the race, he is usually mounted on his horse, Slow Dancer.
During the course of the series, Johnny gradually changes into a more realistic appearance; with slightly wavy hair and a slightly fuller build.
Johnny Joestar is a depressive ex-jockey, who clings to his hope of regaining the use of his legs through the Spin and then the Corpse Parts throughout Steel Ball Run.
Johnny is introduced as a distant paraplegic man whose career was ruined when he was shot in the spine after conceitedly antagonizing a passerby. After Johnny witnesses Gyro's Steel Balls and Spin, and how they enabled him to stand up on his feet for a moment, he becomes determined to follow him and make him teach the Spin, then after discovering the Corpse Parts making his legs twitch, to acquire them.
Johnny stubbornly follows his intentions of following Gyro then track the Corpse. Disregarding the risks or the consequences, Johnny focuses on his goal and puts it above anything else. Several times, Johnny endured severe wounds to reach his goals, notably trying to get on his horse Slow Dancer, which earned him many bruises and a wooden shard through the leg; despite his repeated failures, his determination to participate in the race didn't waver. Inversely, Johnny has no qualm about being violent or killing his opponents to get the Corpse Parts. Gyro Zeppeli has mentioned that Johnny had, "dark determination" in his eyes, indicating a ruthlessness that would make Johnny kill in cold blood. This amoral selfishness still extends to the interest of his loved ones and followed him during his whole life, demonstrated years after the Steel Ball Run, as when his wife Rina was struck with the Rock Disease, Johnny then stole the Corpse to beg it to transfer the disease away from her, not caring who would receive it and suffer in her stead.Yet Johnny isn't completely amoral, for instance objecting to involve the defenceless Lucy Steel in their struggle for the Corpse  and ultimately taking the Rock Disease for himself to save his son.
During the Steel Ball Run race, Johnny was burdened by depression and a subsequent lack of confidence. Notably calling himself a useless person, Johnny's bleak outlook of life stemmed from his youth. Johnny was a timid yet kind child during his childhood, adopting a wild mouse and calling it Danny. Though he was afraid of his harsh father George Joestar, he would try to live up to his expectations. Johnny idolized his older brother Nicholas, but when he died, falling from a horse that was seemingly startled by Danny, Johnny became guilt-ridden, believing that his brother's death was his own fault and that he should have died. He then believed throughout the years that fate itself was taking revenge on him for his crime and that every misfortune he received was in fact deserved. It resulted in his obsession with the blessing of the Corpse, which would reset his karma to a neutral state of “zero” instead of the “negative” state of his curse. It also explains Johnny's rampant lack of confidence and near-constant bouts of panic.  as he thought that fate could at any moment take away his hope of acquiring the Corpse. When Johnny's father disowned him, Johnny shut himself off, creating a facade of conceitedness to hide the sadness this rejection caused him.
Johnny's perspective improved greatly upon meeting Gyro Zeppeli. Having met someone who gave him hope and was genuinely nice to him, Johnny felt grateful for meeting the Italian executioner and treasured this relationship, at one point being willing to abandon the Corpse Parts he had to save his friend. Gyro repeatedly knocked Johnny out of his lack of confidence and helped him get the Corpse Parts, giving him assurance and optimism in life.
As reflected in the multiple ACTs of his Stand Tusk, the improvement was gradual, the key steps of his progress being Johnny discovering the Corpse (ACT 1), then standing up for himself against Soundman (ACT 2), symbolically cleansing himself of his guilt against Axl Ro and being blessed by Jesus Christ's apparition (ACT 3) and finally acquiring the Corpse and regaining the use of his legs (ACT 4). Although Gyro died, Johnny kept a good memory of everything that happened. If during the race, Johnny was uncaring of everyone else save himself and Gyro, only maintaining a polite but cold demeanor at best toward the people he met, Gyro's influence made Johnny slightly more friendly toward people, culminating in his marriage with Rina Higashikata.
In JoJolion, a flashback shows that Johnny maintained that happiness during his life with Rina.
He chose to make Johnny and Gyro around the same age so they could be less formal and more friendly than their original counterparts similar to the Joseph-Caesar relationship from Battle Tendency. Gyro's random jokes and Johnny's use of his spinning nails to accomplish trivial tasks were included to reflect this concept.
- Main article: Tusk
Johnny first seeks Gyro Zeppeli's tutelage in the ways of the Spin in order to regain the use of his legs. Most often, Johnny channels the Spin by the use of his Stand, Tusk; developed first with the power of the Corpse's left hand, and further with Gyro's help. Its form varies, depending on the sort or style of Spin Johnny chooses to employ.
Tusk ACT1 is awakened in the Devil's Palm when the corpse part combines itself with Johnny's left hand, manifesting his Stand with the ability to spin his nails and fire them akin to bullets, and regrowing his nails in seconds.
Tusk ACT2 manifests when Johnny shoots a nail whilst incorporating the Golden Rectangle in a fight against Sandman. Despite the longer regrow time, the nails possess more power and a new ability that lets the holes of the bullets follow the target for a small amount of time.
Tusk ACT3 is the final "base" form for Tusk and manifests when Johnny shoots himself with a Golden Rectangle-empowered nail, enabling him to transfer parts of his body through the holes to shoot from different directions. It was awakened by advice from Jesus in a fight against Axl RO.
Tusk ACT4 manifests itself as a result of Johnny utilizing Slow Dancer's power combined with the golden rectangle, which enables Johnny to fire Golden Spin nail-bullets that have infinite rotation. ACT4 possesses the power to force open D4C Love Train's dimensional wall, and trap anyone hit by it to a single spot indefinitely.
Johnny Joestar has been described as a genius jockey, being one of the favorites of the Steel Ball Run race. His skill allows him to ride across many types of terrain, and challenge even fellow genius jockey Diego Brando. Johnny possesses great knowledge of his horse Slow Dancer, notably its abilities and limits, being able to gauge what Slow Dancer will be capable of at any moment.
- Intelligence: Johnny Joestar proves himself a competent Stand User, being able to use Tusk's abilities to the fullest. Johnny Joestar has occasionally used the terrain and his enemies own power against them, and was perceptive enough to quickly deduce Alternate Diego's time stopping power.
- Marksmanship: When using Tusk, Johnny proves to possess great marksmanship, being able to hit little and/or moving targets, even if firing from odd angles and perspectives, such as when Tusk ACT3 separates his hand from his arm.
- Johnny Joestar and Gyro Zeppeli vs Boomboom Family
- Johnny Joestar and Gyro Zeppeli vs Oyecomova
- Johnny Joestar vs Pork Pie Hat Kid
- Johnny Joestar and Gyro Zeppeli vs Diego Brando and Dr. Ferdinand
- Johnny Joestar and Gyro Zeppeli vs Hot Pants
- Johnny Joestar, Gyro Zeppeli, and Hot Pants vs Ringo Roadagain
- Johnny Joestar and Gyro Zeppeli vs Blackmore
- Johnny Joestar and Gyro Zeppeli vs Diego Brando
- Johnny Joestar vs Sandman
- Johnny Joestar and Gyro Zeppeli vs Eleven Men
- Johnny Joestar and Gyro Zeppeli vs Wekapipo and Magent Magent
- Johnny Joestar vs Axl RO
- Johnny Joestar, Wekapipo, and Diego Brando vs Funny Valentine
- Johnny Joestar and Gyro Zeppeli vs Funny Valentine
- Johnny Joestar vs Diego Brando (Parallel World)
- George Joestar II: Johnny had a complex relationship with his father. In one hand Johnny always sought his father's affection and approval. On the other hand, when George wondered if "God had taken the wrong son", Johnny was deeply saddened and chose to abandon his love for his father, shutting his heart. Johnny confessed to Valentine that he could not think of his own father in the same admiring way Valentine thought of his. Towards the end of the Steel Ball Run race, however, George shows up in the crowd and shows Johnny Nicholas' boots, reconciling with his son at last. Johnny named his son after George.
- Nicholas Joestar: As his elder brother, Nicholas was a model to follow. Johnny admired him since his childhood and feels excessively guilty over his death, thinking that the Universe cursed him for it.
- Danny: While Jonathan and Danny the dog had a shared childhood, this mouse was only a temporary pet for Johnny. When Nicholas died, Johnny believed that Danny and thus him, were responsible for frightening the horse Nicholas was riding and causing his death. Johnny retains good memories of the mouse but also haunting ones, even summoning it when Civil War affects him.
- Rina Higashikata: Johnny and Rina's relationship began after the race and persisted for several years. Both fell in love with each other soon after meeting and they became married, living a happy life for a while. After she becomes ill, Johnny goes searching for the corpse parts as a cure. His love for Rina is so deep he ends up sacrificing himself to save her and their son.
- George Joestar III: Johnny loved his son deeply. When the Rock Disease bounced into him, Johnny sacrificed himself to save George and confided that he was happy to have him in his life.
- His daughter: Daughter he had with Rina. Only listed in the Joestar Family Tree.
- Gyro Zeppeli: Johnny and Gyro are friends, partners in the Steel Ball Run, and also apprentice and master in the art of the Spin. At first, Johnny's determination got Gyro's interest, leading Gyro to assist Johnny in mounting Slow Dancer before the race. After the first stage, Johnny wins the respect of Gyro, leading to Gyro making him his apprentice in the Spin. Over the course of the Steel Ball Run, this apprenticeship grows into a partnership, and then a deep friendship. Despite their opposing personalities causing regular clashes as to how to take on a difficult situation, Gyro and Johnny ultimately get along well and share many moments of friendship. Gyro notably likes to jest with Johnny and tells him bad jokes or miscellaneous songs that Johnny usually appreciates. Due to their regular battles, Johnny and Gyro fight well together, and see each other as valuable allies. Their friendship is such that either one is willing to put himself in danger for the other, and Johnny notably abandoned his Corpse Parts to save Gyro's life. In turn, Gyro often uses life-or-death situations as opportunities to help Johnny master the fundamentals of the Spin and evolve his Stand, Tusk. After Gyro's death, Johnny was devastated, a fact Valentine attempts to use to goad him into sparing him and giving up the Holy Corpse. Gyro stands by Johnny in spirit even after his death, as Johnny returns his corpse to the Zeppeli family in Italy. Gyro's continuous support helped Johnny get out of his depression and enabled him to begin anew. The relationship of the two has similarities to Jonathan's relationship with Will or Joseph's relationship with Caesar.
- Lucy Steel: Johnny and Lucy are allies against Valentine, but do not interact with each other much.
- Mountain Tim: Mountain Tim was first suspicious of Johnny as Benjamin Boomboom tricked him into believing Johnny was killing competitors in the race, but both later became allies in the fight against the Boomboom Family and Oyecomova. Tim notably taught Johnny about the Devil's Palm and Stands.
- Diego Brando: Johnny considers Diego a rival in his quest for the Corpse Parts. Due to Diego's own ruthlessness, Johnny won't hesitate to kill him if he gets in his way. At one point, Diego allies with Valentine to kill Johnny and Gyro, but it doesn't last. While their relationship is more positive than that of their counterparts, Jonathan and Dio, they are enemies all the same.
- Hot Pants: Johnny considers Hot Pants a rival in his quest for the Corpse Parts. He realizes that she is a woman after Gyro kills Ringo Roadagain, but doesn't reveal her true gender to Gyro out of respect for her privacy. After Hot Pants steals Johnny's Corpse Part yet leaves him a small part of the Spine, he is curious about Hot Pants motivations for acquiring it.
- Sandman: Because Sandman didn't go after the Saint's Corpse and acted friendly with the duo, Johnny didn't see him as an enemy. Ultimately, Sandman allied with Valentine and tried to kill Johnny with Gyro and take the Corpse Parts, they thus became enemies. Still, Sandman was indifferent to Johnny, only seeing an internal struggle among the white men he considered enemies that he could exploit.
- Funny Valentine: As both tried to gather the Saint's Corpse, Johnny and Valentine were enemies, but didn't interact much until their single fight. Because of his selfish motive, Valentine saw Johnny as unworthy of the Corpse and tried to kill him, though he treaded carefully with Johnny since Tusk was partly immune to his Dirty Deeds Done Dirt Cheap.
- Diego Brando (Parallel World): As this version of Diego was recruited by Funny Valentine to take the Saint's Corpse from Johnny, it was only natural that the two were enemies. Diego was wary of Tusk, which could move partially in his stopped time, and likewise, Johnny learned of THE WORLD's power and also was wary of it.
- Dr. Ferdinand: Dr. Ferdinand was an assassin and Stand-user hired by President Funny Valentine to murder Johnny and Gyro and gather the Corpse Parts. Using his Stand, Scary Monsters, Ferdinand attempts to transform Johnny and Gyro into dinosaurs bound to his will, and uses a similarly-transformed Diego Brando as a means to that end.
- The Boomboom Family: A family group of three Stand-users, Andre, Benjamin, and L.A. Boomboom, who use their talents to murder competitors in the Steel Ball Run, eventually targeting Johnny and Gyro as well. After a failed attempt to frame Johnny for the murder of several other competitors, they attempt to assassinate Johnny, Gyro, and Mountain Tim directly, failing when Johnny first develops his Stand, Tusk.
- Oyecomova: Oyecomova is a Neapolitan assassin and terrorist who once encountered Gyro Zeppeli before he developed his Stand, Boku no Rhythm wo Kiitekure. He attempted to use this ability to assassinate Gyro, and Johnny in the process, but proved no match for their combined skills in the Spin.
- Ringo Roadagain: A duelist working for Funny Valentine, Ringo Roadagain holds the philosophy that a true man must gamble his life against others in order to prove his worth. He notes that Johnny has the "dark determination" to kill if need be and thus would have a chance against him. Nevertheless, after incapacitating Johnny, he is defeated by Gyro.
- “Hey, you! What's with that Steel Ball?”
- “This story is the tale of me starting to walk. Not in the physical sense... but in an adolescence to adulthood sort of way... (この「物語」はぼくが歩き出す物語だ。肉体が…………という意味ではなく青春から大人という意味で……Kono `monogatari' wa boku ga aruki dasu monogatari da. Nikutai ga………… to iu imide wanaku seishun kara otona to iu imi de……)”
- “There was a beauty that existed on this beach... a beauty within the darkness. I was drawn to something on this beach. Will there be a light called hope here...?”
- “The Spin... All hope... it's all in the Spin! I want to know more... more about the Steel Balls...”
- “You ran well. Old horse, you've gained a lot of experience from this race. Riding on the rough ground, going across that forest, and rushing downhill with no errors. And despite how much you've been sweating, you can still keep on going...! Your legs are in perfect shape! Your breathing is also in good spirits! We're only at 40-50 horse lengths away! But he dashed ahead too early! He'll be tired! Let's surprise this Gyro Zeppeli!”
- “A race is a race... there's no reason for you to wait for me... I'll catch up with you after I wipe up my blood!”
- “This is why I signed up for this race... to know the secret of the Spin and to learn it myself. I'll do it! If I don't, everything will end here!”
- “My nails just shot out from my lame feeeet!”
- “I will never hand over this corpse! This has become my hope!”
- “This ability has far surpassed a simple nail… it’s a Tusk. From now on I will call this Tusk. (これはもう爪を超えた………「牙」だ。これからは「
牙」と呼ぶ！Kore wa mō tsume o koeta………`kiba' da. Korekara wa `tasuku' to yobu!)”
- “It wasn’t supposed to be my brother, it should have been me who was taken. I should have been the one to die… That’s why I had to pay the price. Someday, Fate would catch up with me.”
- “I understand now. I’ve realized! Where I should shoot my nail bullets…!”
- “I am not wavering anymore!”
- “We’re going to go and corner Dio and take the Left Eye. But, of course… he’ll relatiate, using his Stand. If we ease up on him, he’ll kill us both. I just want to know what you’ll do when he starts fighting back… I’m prepared to shoot him, if need be.”
- “Shit. Just a little more, dammit! I’m sure it’s just a little more! I want to get my hands on that corpse no matter what! I don’t care about living or dying or who’s just and who’s evil! I don’t even give a fuck about the corpse being a saint or whatever!! I’m still negative! I want to get up to zero! If I can get the corpse, I can get my negative back to zero!”
- “Do you know what a fetish is? I’ve got a little fetish… This is… well, huh… with girls…. Do you know what a bug bite fetish is…? When girl’s arms or legs or something get bitten by a mosquito and their skin swells and gets a little red. That excites me! That’s all! Don’t tell anybody! Ah, I knew it, I take it back! I told you I’d wish I hadn’t said it!”
- “It’s truly, truly been… a very long roundabout path… (本当に本当に、なんて遠い廻り道…Hontōni hontōni, nante tōi mawari michi…)”
- “The perfect rotation energy… and I still have one nail bullet left.”
- “Gyro, for this reason… this was the reason for “lesson 5”. Thank you… Thank you, Gyro. I truly… truly… thank you… I can’t find any other words to express it.”
- “Tusk ACT 4. The sacrifice, President Valentine! Which do you think it will really be? Ora ora ora ora ora ora ora ora ora ora ora ora ora ora ora ora ora ora oraaaah!!!!!!”
- “Gyro… I’m sorry… I’m really sorry… I wanted to believe… I really wanted to believe the President… Goodbye. Gyro… goodbye. (ジャイロ…すまない...すまなかった…本当に...さようなら...ジャイロ…信じたかった…本当に…大統領を信じたかった…さようならジャイロ…さようなら。Jairo… sumanai... sumanakatta… hontōni... sayōnara... Jairo… shinjitakatta… hontōni… daitōryō o shinjitakatta… sayōnara jairo… sayōnara.)”
- “Who knows that the Corpse is really important…? Who understands the Corpse? In this world, it is I alone, Johnny Joestar. There’s no way I’ll hand it over to anyone… the only one with the right to end this is me!”
- “In this situation… I wanna say something tough… like Gyro would. (この状況…ジャイロのように……タフなセリフを吐きたい。Kono jōkyō... Jairo no yō ni…… tafuna serifu o hakitai.)”
- “This is a story of revival… How I was literally able to start walking again… and thinking back, I was constantly praying the whole journey… even this cross-continental race by horse was a journey of prayer. Praying for the weather tomorrow. Praying that when when we wake up the next day there would be a road on the land. Praying that we would have food and a place to sleep. Praying that our campfire would light. And while these common things would repeat, prayer that my friend and the horses would be okay. And we crossed each river one by one. Now… I have crossed the final river.”
- “Why don’t we pray… that we have a safe voyage… crossing the Atlantic Ocean, and getting you back home… home. Let’s go home. (「祈って」おこうかな………航海の無事を………この大西洋を渡って家に帰ろう………家に…帰ろう…`Inotte' okou ka na……… kōkai no buji o……… kono Taiseiyō o watatte ie ni kaerō………ie ni… kaerō…)”
- “Why did it have to be the person I loved...? Why did the disease have to choose her...? Just one time... just this once... please, forgive me. Can't you just give it to someone I don't know in her place...? As long as my wife is spared, I'm okay with that... just this once.”
- “I won't use the Holy Corpse anymore. It will bring misfortune to someone somewhere. George Joestar, I'm glad I was able to meet you... that is enough for me.... I couldn't exchange that for anything. I have found a happiness... that cannot be replaced.”
- “[The disease] will be exchanged for something of equivalent value. But I have something here I couldn't exchange for anything.”
- In the first chapter, his name is written in Japanese as "ジョニー", whereas from the second chapter on, it is written as "ジョニィ". Both have the same pronunciation, however.
- According to Araki, he always wanted the protagonist of Part 7 to fight against nature itself while at the same time, having his struggles help him on a path to maturity.
- Johnny reveals to Gyro that he has a paraphilia for women with bug bites.
- Johnny's voice actor in the Bandai Namco games, Yuki Kaji, also voices Koichi Hirose in the Part 4 TV Anime.