The Tour Guide is a woman who works at the Dimmsdale Museum of Science and Natural History.
This tour guide guides A.J.; and Chester McBadbat, Sanjay, and Elmer (the three of whom A.J. dragged along with him) to the new solar system exhibit that A.J. eagerly wanted to see, but to their surprise a naked Timmy was standing in the middle of the exhibit trying to hide, and ended up unintentionally "mooning" all of them.
She wears a lavender dress uniform with black shoes, and has reddish-brown hair with greens eyes.