PREHEAT oven to 450°F. Place pizza crusts on baking sheets. Spread 1/4 cup of the RedHot Buffalo Wings Sauce on each crust, then sprinkle evenly with celery.
TOSS chicken with remaining 1 cup of the RedHot Buffalo Wings Sauce. Spoon chicken over pizza crusts. Sprinkle with mozzarella and blue cheese.
BAKE pizzas 12 minutes or until crust is crispy and cheese is melted. Drizzle ranch dressing on each pizza to serve.