Remove chicken from packaging and remove giblets (if included), saving giblets for another use. Place chicken on a rack over a rimmed sheet pan or roasting pan and lightly season all over with salt and pepper.
Loosen chicken skin and rub seasoned butter under skin, coating evenly over all parts of the chicken. Place chicken breast side down onto rack and bake.
Roast until chicken is golden brown and a thermometer inserted into the thickest part of a chicken thigh reaches 155ºF, about 50-60 minutes. Remove from oven and let chicken rest in roasting pan 10 minutes. Transfer to a cutting board and carve. Serve chicken with pan drippings poured over.