Not in Grape Nut Flakes, but I'm not too sure about actual Grape Nuts. I would go to the store and check the ingredients on the nutrition label on the side of the box. That would probably tell you.
According to the Post Cereal website, the name is believed to come from the "grape sugar" that formed while baking, and the "nutty" flavor that they had. See related link.
Many things that are called nuts actually aren't by the strict botanical definition. For example: almonds, Brazil nuts, cashews, macadamias, peanuts, pecans, pine nuts, pistachios and walnuts are all...