Preheat your oven to 400°F (200°C).
In a medium bowl, combine the Greek yogurt, minced garlic, lemon juice, dill, olive oil, salt, and pepper. Mix well to create the tzatziki sauce.
Spread half of the tzatziki sauce evenly over each naan bread.
Top each naan with shredded chicken, diced cucumber, cherry tomatoes, red onion, and crumbled feta cheese.
Place the naan pizzas on a baking sheet and bake in the preheated oven for about 10-12 minutes, or until the edges are golden and the toppings are heated through.
Remove from the oven and drizzle with any remaining tzatziki sauce before serving.