Preheat crock-pot to high heat. Wash and pat dry whole chicken, making sure to remove any giblets. (Either discard giblets or save to make stock or gravy). Loosen skin from breast by running your hand between the skin and meat. Cut margarine into 8 pieces and place between skin and meat. Coat chicken with olive oil. Tuck wings beneath chicken.
Place chicken in crock-pot. Sprinkle with seasoned salt, Creole seasoning, and freshly ground pepper.
Place the lid on the crock-pot and cook on high heat for 3 hours. Reduce heat to low and continue cooking an additional 2 to 3 hours.