Preheat your oven to 350°F. Lightly grease a 9×13-inch baking dish.
In the greased baking dish, layer the corned beef, topped with sauerkraut, drizzle thousand island dressing evenly over the sauerkraut, followed by the cubed rye bread on top and sprinkle shredded Swiss cheese evenly over the bread.
Cover the dish with aluminum foil to ensure even cooking.
Bake in the preheated oven for 25 minutes. After 25 minutes, remove the foil and bake for an additional 5 minutes, or until the cheese is melted and bubbly.