Yes, peanut butter is gluten free. In its purest form it's made of only peanuts, and often salt. If you have Celiac Disease or are on a strict gluten free diet for other reasons and have to avoid cross contamination, commercially prepared peanut butters can sometimes be unsafe. It's always important to read the labels carefully because they could say "made in a factory where other items are prepared with wheat," or something to that effect.