In a mixing bowl, combine the Greek yogurt, diced cucumber, chopped dill, lemon juice, minced garlic, and a pinch of salt and pepper. Stir well until mixed and set aside.
Roll out the pre-made pizza crust on a lightly floured surface to desired thickness. Transfer it to a parchment-lined baking sheet or pizza stone.
Evenly distribute the shredded chicken on top of the pizza crust.
Spoon the prepared tzatziki sauce over the chicken, spreading it out gently but leaving some chicken visible.
Sprinkle the shredded mozzarella cheese evenly over the tzatziki. Top with thinly sliced red onion for added flavor.
Lightly brush the edges of the crust with olive oil for a golden finish.
Place the pizza in the preheated oven and bake for 12-15 minutes or until the crust is golden and the cheese is bubbling.
Once baked, remove from the oven and let it cool for a couple of minutes. Slice the pizza and serve hot, optionally garnished with additional dill.