She is Sweetie Belle's older sister and dreams of becoming a designer for Princess Celestia. She also once hoped to marry Celestia's nephew Prince Blueblood, until she actually met him, where he turned out to be snobbish, rude, and self-centered. Later, she becomes aware of Spike's crush on her but only sees him as a friend. Rarity's magic has been demonstrated to involve both telekinesis and finding nearby jewels buried underground. She represents the element of generosity.

Rarity sometimes became too impatient with Sweetie Belle, causing a discussion for being supported just like seen in The Sisterhooves Social and Sleepless in Ponyville. In Rarity takes Manehattan, during the reprise of the song Generosity, Rarity thinks that was abandoned after by her friends, after treat them bad and pardons to them and finally to Sweetie Belle in For Whom the Sweetie Belle Tolls.

Sweetie Belle has a white body, green eyes, and a pink and lilac, curly mane and tail. Since "Crusaders of the Lost Mark", her cutie mark has been a purple striped emblem with a musical note in the middle with a star in it.