Preheat oven to 400°F In a large non-stick skillet, heat oil over medium-high heat . Cook the onion until tender, about 5 minutes. Add turkey, breaking up pieces with the back of a spoon. Cook until browned, about 8 minutes. Set aside.
Place Pizza crust on a baking sheet. In a small bowl, combine pizza sauce with ketchup. Spread over crust. Top with turkey mixture, cheese, tomato slices, red onion and pickles, if using. Bake on middle rack of oven until crust is golden and cheese is melted and bubbling, about 10 minutes.