In a large mixing bowl, combine the ground chicken, Panko bread crumbs, Italian bread crumbs, dried onion, seasoned salt, garlic powder, and dry Ranch dressing mix. Use your hands to mix everything together until just combined. Be careful not to overmix, as this could lead to tough burgers.
Divide the mixture into four equal portions and shape them into patties. Make sure to create a slight indentation in the center of each patty to prevent them from puffing up while cooking.
Heat a griddle or grill pan over medium heat and add the butter. Once the butter melts and starts to bubble, carefully add the patties to the pan. Cook for about 5-6 minutes on one side until golden brown. Flip the patties and cook for another 5-6 minutes, or until they reach an internal temperature of 165°F.
In the last minute of cooking, place a slice of cheddar cheese on each patty. Cover the pan with a lid to help the cheese melt beautifully.
Once the cheese has melted, remove the patties from the heat. Toast the hamburger buns on the griddle for a minute if you desire some extra crunch. Assemble your Cheddar Ranch Chicken Burgers by placing the patty on the bun and adding your favorite toppings, such as fresh lettuce and a drizzle of ranch dressing.