To make these Easy Crockpot Meatballs gluten free, use certified gluten-free frozen meatballs and a gluten-free BBQ sauce. Also confirm that the grape jelly is free from hidden gluten-containing additives if needed for strict dietary requirements. Because processed meatballs and sauces can vary by brand, always check labels carefully if preparing this recipe for someone with celiac disease or a strict gluten-free diet.