Preheat oven to 425 degrees F. Lightly grease a pizza pan. Cook bacon and drain on paper towels. Slice chicken breasts and cook in a large skillet over medium-high heat until no longer pink and juices run clear. Cool and set aside.

Prepare pizza crust (depending on if you purchase or make your own) and bake for 7 minutes in preheated oven until it begins to turn golden brown. Spread ranch dressing over partially baked crust. Sprinkle on mozzarella cheese. Place tomatoes, green onion and chicken on top of mozzarella cheese. Top lastly with Cheddar cheese. Return to the oven for 20 minutes, until cheese is melted and bubbly.