Snow White is a character from the 1937 Disney animated movie, Snow White and the Seven Dwarfs. She is one of the Princesses of Heart whose heart was required to open the final door in Kingdom Hearts.
 Kingdom Hearts Birth by Sleep
Snow White's first appearance in Kingdom Hearts Birth by Sleep is when she is encountered by Terra in a meadow in her home world of Dwarf Woodlands, the girl not at all surprised to see the Keyblade wielder standing before her. Terra is told by the Queen to kill her, but he decides to put aside the plan. When the Unversed arrive, Terra summons his Keyblade to defeat them, but he also frightens Snow White and she flees into the woods in fear.
After Ventus arrives in Dwarf Woodlands and meets the Dwarfs, he hears Snow White scream and finds that she has been cornered by Unversed and monsters that inhabit the trees of Dwarf Woodlands. He manages to take her to safety at the Seven Dwarfs' house where she stays until the Dwarfs come back. Her beauty and kindness persuades them to let her stay and keep her company. As soon as Ven returns after checking the woods, she tells them what had happened when she fled into the woods, and about meeting Terra. The Dwarfs claim that it was Terra who'd sent the Unversed after her, but Ven disagrees and Snow White is willing to believe.
By the time Aqua arrives, Snow White has already taken a bite on the poison apple and fallen into a deep slumber and placed in a glass coffin by the Seven Dwarfs. Later on, Aqua arrives with the Prince, who turns out to be Snow White's first love and the only person who can break the spell. He kisses her on the lips and awakes her from her slumber. She takes her farewell to the Dwarfs before the Prince sweeps her away.
Sometime after the battle at the Keyblade Graveyard, she is seen with the Prince and the Dwarfs in the meadow where her little friends throw flower petals around them. She and the Prince look at the petals in delight.
 Kingdom Hearts
Once all seven of the maidens have been gathered, Maleficent has their hearts extracted in order to open the keyhole from Hollow Bastion and release the power within it. When the princesses' hearts are restored, Snow White and the other five princesses wake up from their slumber and use their combined power to shield the darkness inside in order to keep it from spreading throughout the universe. They are not able to keep it up for long, possibly because Kairi, the seventh princess, is not present, but they manage to do so long enough for Sora to return and seal the keyhole. After it was sealed, Snow White remains in Hollow Bastion with the princesses, and Beast, Leon, Yuffie, and Aerith.
When Kingdom Hearts was sealed she is returned to her own world.
 Kingdom Hearts II
In Kingdom Hearts Birth by Sleep, Snow White has rather short, wavy, black hair, brown eyes, and somewhat pale skin. She also has long eye lashes and wears red lipstick and a red ribbon in her hair tied in a bow. Clothing-wise, Snow White wears a yellow skirt and blue bodice. The sleeves of her dress are short and puffy, azure in color, and sport several red teardrop-shaped symbols on them. There is a high, white collar on the back of her dress. Snow White also wears gold slippers with a small, white bow on the front of each one and a red cape tied around her neck by a brown strip of cloth. In Kingdom Hearts, Snow White looks largely the same, albeit with slightly longer hair and minor color differences in her clothing.
Snow White can communicate with animals with her singing voice.
Because Snow White is a Princess of Heart, her heart can be used to summon the Keyblade of People's Hearts, which can open the door to Kingdom Hearts. Furthermore, she can use her heart's light to hold back darkness, and her lack of darkness allows her to keep her body if her heart is stolen. The Princesses, together, were also able to upgrade Sora's Fire spell.
In Kingdom Hearts Birth by Sleep, Snow White becomes a summonable D-Link ally for Ventus and Aqua after the separate events of her home world. As a D-Link, she can project her power to aid them in battle.
While in link with Snow White, the characters can create whirlwinds of flowers or seven colored jewels to attack the enemies. Her Deck Commands are also the names of the Seven Dwarfs: Sleepy (Sleep), Grumpy (Treasure Raid), Happy (Confetti), Dopey (Mini), Doc (Curaga), Bashful (Warp), and Sneezy (Aeroga).
In Snow White and the Seven Dwarfs, Snow White is a born princess, but after her father died, her stepmother, the Queen, forced her to work as a servant in the fear that her stepdaughter might one day surpass her in beauty. Since Snow White's beauty comes from both outward appearance and inner kindness, the Magic Mirror tells the Queen that the princess has become more beautiful than she. The Queen sees this for herself, and is enraged when an unnamed Prince is smitten with Snow White upon hearing her voice.
The Queen orders a huntsman to take Snow White into the forest and kill her. Unable to bring himself to commit the crime, the huntsman warns Snow White to run away and never return. While escaping into the forest, she meets seven dwarfs and comes to live in their cottage. The Queen makes another attempt to kill Snow White by transforming herself into an old hag an tricking her stepdaughter into biting a poisoned apple, which places her in an eternal slumber. Though the queen is initially successful, she is soon discovered by the dwarfs, who chase her to a cliff from which she falls to her death after the ground on which she stands is struck by a bolt of lightning. The dwarfs place Snow White in a coffin of glass, and they mourn her apparent demise, until the Prince finally finds Snow White and awakens her with a kiss. Snow White is then swept away to marry the Prince, bidding a grateful farewell to the dwarfs one by one.