The Kingdom Hearts series famously offers players a one-of-a-kind cross-over adventure, blending Disney films with Square Enix's Final Fantasy games. The original game hosted a motley crew of characters, but the Final Fantasy inclusions often stole the show. Like Leon (Squall) and Cid, many of these characters play a direct role in Sora's story -- not just the transitory plot on Disney worlds. Quite a few notable Final Fantasy characters, from Sephiroth to Tidus, make appearances, but also a few underdogs too.
Kingdom Hearts' main character, Sora, was recently announced as the final Guest Fighter in Super Smash Bros. Ultimate, but he'll be starred without any of his allies. Though Sephiroth and Cloud have both been featured in Kingdom Hearts games and are also among Super Smash Bros. Ultimate's roster, the two Final Fantasy VII characters are not representing their Kingdom Hearts appearance. That said, Sora's rubbed elbows with countless Final Fantasy friends before in his own titles. Here's every Final Fantasy character that appeared in the original Kingdom Hearts game.
Tidus
Tidus makes an appearance as one of Sora's childhood friends on Destiny Islands. Though his interactions with Sora in-game amount to little more than a couple of conversations and the option to spar with him, it's implied by the familiarity of their conversation that they have been friends for some time. The Kingdom Hearts version of Tidus is aged down from his original Final Fantasy X appearance.
Tidus is the main protagonist of Final Fantasy X, where he joins the Summoner Yuna on her pilgrimage to defeat Sin. The Tidus featured in Kingdom Hearts does not have any of his equipment but does retain his swordsmanship, which he performs using a long stick.
Wakka
Wakka appears in Kingdom Hearts at the beginning of the game on Destiny Islands. He's also available as one of Sora's sparring partners. Wakka has a few things to say to Sora during his time on Destiny Islands, and he even helps point lost players in the right direction at one point. Though it seems Sora and Wakka have known each other for a while, the Wakka in Kingdom Hearts is a much younger version than the original in Final Fantasy X.
Wakka is a supporting character and party member in Final Fantasy X. While he doesn't look like his original self, he still has his Bliztball and prowess with the item.
Selphie
Selphie is the third Destiny Islands friend alongside Tidus and Wakka at the beginning of the game. She's only got a few things to say, but she's available to spar with if Sora wants to refine his skills. Like her two other young companions, the Kingdom Hearts version of Selphie is a more youthful interpretation than that of her original appearance.
Selphie is a supporting character and party member from Final Fantasy VIII. Selphie was a master of nunchaku when she made her debut, and in Kingdom Hearts, she shows that off with her mastery of weaponizing the jump rope.
Cloud
Kingdom Hearts introduces its take on Cloud when Sora first visits the Hercules-based Olympus Colosseum. Facing off in a tournament as Hades' champion, Cloud finds himself a pawn to the Disney villain's scheme to lay low Hercules. Regardless of how Sora's encounter with Cloud goes, the two escape then Herc intervenes. If players emerge victorious when fighting Cloud, he'll surprise them with a little gift later on. Cloud can also be fought in other tournaments in Olympus Colosseum throughout the game.
Cloud Strife is the main protagonist in Final Fantasy VII and its recent remake. However, unlike his appearance in Final Fantasy VII, Kingdom Hearts' Cloud is garbed in a combination of his SOLDIER armor and Vincent Valentine's attire. This said, he does still have his Buster Sword, though it appears wrapped in bandages.
Yuffie
Yuffie makes an appearance in Kingdom Hearts during Sora's first visit to Traverse Town. After his battle with Leon, Sora awakens in a room with a woman who he first mistakes for Kairi. "The Great Ninja Yuffie" is quick to correct Sora and then aids the hero in battling to the source of Traverse Town's Heartless infestation. Yuffie often appears along with Leon, Cid and Aerith, all originating from Hollow Bastion before its fall. The four help Sora several times throughout his journey, both in Traverse Town and later in Hollow Bastion.
Yuffie Kisagari is a supporting character and party member in Final Fantasy VII and the lead protagonist in this year's Final Fantasy VII EPISODE INTERmission DLC. She's a master ninja and proficient with her oversized throwing weapons in all appearances.
Leon (Squall)
Arguably, the most essential Final Fantasy character is Squall, known as Leon in Kingdom Hearts. Soon after Sora arrives in Traverse Town, Leon challenges him to a fight, gauging his strength. From there, Leon plays an instrumental role in guiding Sora when all paths seem closed, often helping Sora locate new worlds or offering vital advice. Helping Sora throughout the course of his journey, Leon eventually helps retake his former home, Hollow Bastion.
Squall Leonhart is the main protagonist in Final Fantasy VIII, where he joins his fellow SeeD students to save the world from a deranged sorceress. Squall sports an iconic mid-cut leather jacket with fur trim in both his original depiction and in Kingdom Hearts, though his leather jacket has short sleeves in the latter. In both appearances, he wields a sword-gun hybrid called a Gunblade.
Aerith
Aerith resides in Traverse Town for most of the first Kingdom Hearts game, but she's catching up with Donald and Goofy while Leon and Yuffie tend to Sora. Though Aerith isn't often at the forefront of situations like Leon and Yuffie are, she's always there backing them up -- even when it came to returning to the Heartless-overran Hollow Bastion.
Aerith is a supporting character and party member in Final Fantasy VII and in 2020's Final Fantasy VII Remake. Aerith is a master of healing magic in her Final Fantasy appearances, akin to a White Mage. In Kingdom Hearts, Aerith is not confronted with combat and thus doesn't showcase any potential ability. That said, she is responsible for upgrading Sora's Cura spell to Curaga.
Cid
Sora has only one mechanic in Kingdom Hearts, and that's Cid. Sora first meets Cid in Traverse Town while he's tending to a friend's general store. After Sora learns his true profession, he sets up shop a short distance away and always lends a hand whenever players need Gummi Ship upgrades. He's originally a resident of Hollow Bastion and aids Leon, Yuffie and Aerith in their fight to retake their home.
Cid is a supporting character and party member in Final Fantasy VII. His appearance in Kingdom Hearts and his original appearance are nearly identical aside from clothing. In Kingdom Hearts, he wears a white tee shirt and blue pants as opposed to a blue aviator jacket and flight goggles worn in Final Fantasy VII. He's also swapped his cigarette for a toothpick and is without his spear.
Sephiroth
One of the surprise inclusions in Kingdom Hearts was Sephiroth. Featured as a secret boss only encounterable in Olympus Colosseum's Platinum Match, Sephiroth offered the ultimate challenge in Kingdom Hearts. Sephiroth's cinematic entry is all players see before their battle begins, going right into the fight without a word. While he didn't play a pivotal role in Sora's journey or the overall narrative, he did prove to be among Sora's most dangerous adversaries.
Sephiroth is the antagonist of Final Fantasy VII and sort of last year's Final Fantasy VII Remake. Sephiroth is famous for his oversized sword, Masamune, and bright silver hair against his black trench coat. Much of this is intact in Kingdom Hearts, though he does permanently sport the titular one wing.