Preheat your oven to 350 degrees.
Combine the ground beef, onion, bread crumbs, egg, and water, using your hands to mix everything thoroughly. Roll into 1½ inch balls and place on a parchment paper-lined baking sheet. Bake for 20 minutes.
While the meatballs are baking, combine the ketchup, bbq sauce, jellied cranberry sauce, and brown sugar in a medium-sized pot. Bring to a simmer.
Once the meatballs are done, add them to the cranberry mixture and let cook for an additional 10-15 minutes. Serve hot.