Mix bison, mustard, oregano, cumin, onion powder, paprika, sage, and celery salt together in a bowl. Form meatballs approximately 1 1/2-inch diameter in size.
Heat olive oil in a non-stick skillet over medium-low heat, swirling to cover bottom of the skillet. Add meatballs and cook undisturbed, about 4 minutes. Continue to cook, turning meatballs until browned evenly on all sides, about 6 minutes more. An instant-read thermometer inserted into the center should read at least 160 degrees F (70 degrees C).
