Old Chicago Pizza Restaurant is a long-running pizzeria in Petaluma, CA, housed in a historic building and specializing in authentic Chicago-style deep-dish pizza. With a 4.6-star rating from over 1,100 reviews, it's a trusted spot for locals craving that signature thick, crispy crust. Whether you're a deep-dish devotee or new to Chicago pizza, this Petaluma staple delivers a classic experience.