In a microwave safe bowl, heat the jellied cranberry sauce for 2 minutes. Just enough to make it stirrable.
Whisk in the bbq sauce. The cranberry sauce will look lumpy, and that's okay. It will melt down as it cooks.
Dump meatballs into the crockpot, and pour the sauce on top. Give the meatballs a quick stir to help cover them in sauce.
Cook on high for 2-3 hours, or low for 4.
Serve as an appetizer or over rice for a meal.