Gather all ingredients. Preheat the oven to 350 degrees F (175 degrees C).
STEP 2
Place chicken in a roasting pan; season inside and out with onion powder, salt, and pepper. Place 3 tablespoons of butter in the cavity; arrange remaining butter on the outside.
STEP 3
Cut celery into 3 pieces; place in the chicken cavity.
STEP 4
Bake uncovered in the preheated oven until no longer pink near the bone and juices run clear, about 1 hour and 15 minutes. Use a thermometer to check for 165 degrees F (74 degrees C).
STEP 5
Remove from oven, baste with drippings. Cover with foil and let rest for about 30 minutes before serving.