Cid is a character introduced in Kingdom Hearts who originally appeared in Final Fantasy VII.
Though each Final Fantasy game each has had its own Cid since Final Fantasy II (and remakes of the original Final Fantasy mentions a Cid as well), the Cid of the Kingdom Hearts series is that of Final Fantasy VII, Cid Highwind. As a Cid, he bears the trademark of his association with machinery and airships, or Gummi ships in this case. Like Cid Highwind, the Kingdom Hearts Cid is a pilot and is rather uncouth behavior with a good heart. However, what is not retained is his smoking habit, thus the lack of the box of cigarettes strapped to his goggles and his trademark cigarette in his mouth, which is replaced by a toothpick to produce a similar image, and more importantly, his signature foul mouth, with many of these foul words replaced by symbols in the English translation. In addition, his attire resembles neither his original design nor his appearance in Final Fantasy VII: Advent Children.
Cid, along with Cloud, Aerith, Tifa, Yuffie, and Leon were originally set to appear in Kingdom Hearts Birth by Sleep. However, in the final release, they were removed from the game because, according to Nomura, there were too many plot lines already, and it would have gotten confusing.
 Kingdom Hearts
Cid is one of the first characters that Sora meets and befriends after arriving in Traverse Town. He runs an accessory shop in the center of the town's 1st District. At one point, Cid sends Sora out to deliver an old, broken book—The Adventures of Winnie the Pooh—to Merlin. When Sora and company return to Traverse Town with unusual gummis, he explains Navigation Gummis to them and offers to install that ones they find on their Gummi Ship. He turns over the accessory shop to someone else, and he begins selling Gummi Ship parts outside the synthesis shop. This is true to his Final Fantasy VII counterpart, as he is an expert on air travel. In fact, most incarnations of Cid in the Final Fantasy series have been associated with airships and mechanics.
Like Leon, Merlin, and other important characters met in Traverse Town, Cid was originally from Radiant Garden. When Leon, Yuffie and Aerith depart to Hollow Bastion, he remains behind in Traverse Town, and seemingly becomes Kairi's only guardian. After Sora sealed Kingdom Hearts, he returns to his world, meeting up with Cloud on the way.
 Kingdom Hearts: Chain of Memories
Cid appears in Castle Oblivion, in the memory-based version of Traverse Town. Like the other characters appearing out of Sora's memory, he doesn't remember Sora, but knows his name.
 Kingdom Hearts II
Cid is a member of the Hollow Bastion Restoration Committee, working out of Merlin's home. He fills Sora and company in on the goings on in town when the drop by. Cid seems to have a rivalry with Merlin, with Cid favoring technology over magic and Merlin favoring magic. He is a computer expert, and manages to create a program which helps Sora and Tron defeat the Master Control Program.
Shortly after entering the Datascape's version of Traverse Town, Data-Sora meets Cid outside the accessory shop. Cid asks Sora to help search for Huey, Dewey, and Louie around town. After Sora brings back Huey and Dewey, Cid gives Sora a piece of the world's Keyhole.
Unlike his fellow Compilation of Final Fantasy VII characters, Cid's appearance in the Kingdom Hearts only vaguely resembles his look in the Compilation media. He retains his goggles and wears a necklace with a rectangular charm that resembles one he wore in Final Fantasy VII: Advent Children (though it is made of wood and secured by a rope here, whereas in Advent Children it was metal and secured by a thin chain, rather resembling a military dog tag). Cid's short hair is blond, albeit styled a bit differently and much brighter than his original incarnation's platinum blond hair.
His eyes are blue and he has some stubble on his chin. Cid chews on a toothpick instead of his normal cigarette due to the younger demographic of the Kingdom Hearts series. He wears a white T-shirt with two buttons descending from the neck. His baggy pants are blue and have a very wide, orange waistband with thin, vertical stripes on it. Cid's pants are worn rather high, with the waistband coming up to just under his ribcage, similar to the way he wore them in the Final Fantasy VII games. Cid also wears grey socks and black shoes.
Cid Highwind made his debut in Final Fantasy VII as one of the playable characters, and the last non-optional party member.
Was to be the first man to ever go to the outer space, Cid is forced to abandon his dreams by his very own assistant, Shera. As he is about to take off in the "Shinra No. 26", he decided to abort the launch because Shera was still in the engine room, checking an oxygen tank as it showed some minor anomalies.
Later, the new president of Shinra, Rufus, held a meeting with him. Cid thought he was going to re-initiate the Space Program, but it turns out Rufus planned to take Cid's airplane, the "Tiny Bronco", to chase after Sephiroth. After Cloud and the others defeated Palmer (who was going to steal the airplane under Rufus's order) and accidentally turned on the airplane, both the party and Cid made an escape from Rocket Town and landed on the sea. Cid then decided to join the party to oppose Shinra and defeat Sephiroth.