Melt the butter in a large skillet over medium-high heat. Season the chicken with salt and pepper and cook until golden brown, about 3 minutes. Place in a slow cooker.
Reduce the heat to medium. Add the cream of mushroom soup and cream of celery soup to the skillet and heat until creamy. Pour over the chicken in the slow cooker, then stir in the olives, mushrooms, wine, and flour.