If one is serving large, 2-ounce meatballs, then one can serve two meatballs per person. However, the number of meatballs to serve per person can vary depending on the size of the meatballs.
If one makes smaller, 1-ounce meatballs, then four meatballs should be served per person. Deciding on the number of meatballs to serve at a large gathering also depends on what other foods are accompanying the meatball. For example, the portion of meatballs served with spaghetti is different than if one serves meatball sandwiches. Likewise, the portion per person may be more if one serves small cocktail meatball.