GLUTEN FREE CONFIDENCE SCORE: 5/10
Potatoes are mostly gluten-free. However, at restaurants, if they are cooked in a fryer with battered fried foods that contain gluten there is a problem. It means the oil is contaminated and nothing prepared in that fryer is considered gluten-free. So bottom line, gluten-free foods that are cooked in a gluten fryer are not gluten-free any longer.
BTW, here are some of the national restaurant chains that offer gluten-free French fries in some or all of their locations:
Five Guys Burgers
In grocery, check the label.