Peach has appeared in all of the Paper Mario games.
In Paper Mario, she is kidnapped by Bowser and placed in his castle. With the help of Twink, a Star Kid, she managed to find a secret passage out of her room. She uses this passage to find out secret information about Bowser's plans and relay it to Mario. Periodically, players could play as Peach in between segments of the story.
Paper Mario: The Thousand-Year Door saw Peach being used by the Shadow Sirens to eventually become the host of the Shadow Queen. In Paper Mario: Sticker Star, she is kidnapped by Bowser when he crashes the Sticker Festival, and in Super Paper Mario, she is forced by Count Bleck to marry Bowser to form the Chaos Heart.
