Preheat the oven to 475°F (245°C). If using a pizza stone, place it in the oven during preheating.
On a lightly floured surface, roll or stretch the pizza dough into a 12-inch circle.
Transfer the dough to a pizza peel or a parchment-lined baking sheet.
Spread the ranch dressing evenly across the dough, leaving a 1-inch border for the crust.
Sprinkle 1 cup of the mozzarella cheese over the ranch base.
Evenly distribute the cubed chicken, crumbled bacon, and red onions over the cheese layer.
Top with the remaining 1 cup of mozzarella cheese and a sprinkle of dried oregano.
Bake for 12 to 15 minutes, or until the crust is golden brown and the cheese is bubbling and slightly browned.
Remove from the oven and garnish with fresh chives.
Allow the pizza to rest for 5 minutes before slicing and serving.