Preheat your oven to 350°F (175°C) and lightly grease a 9x13-inch baking dish.
In a large bowl, mix together the shredded chicken, cream of chicken soup, and sour cream until the mixture is smooth. Spread this filling evenly into the prepared baking dish.
In a separate bowl, combine the crushed crackers with the melted butter, ensuring that the crackers are well-coated.
Evenly sprinkle the buttery cracker mixture over the chicken layer in the baking dish.
Bake in the oven for approximately 30–35 minutes, or until the casserole is hot and bubbly, featuring a golden-brown topping.
Allow the casserole to cool for 5 minutes before serving.