Preheat the oven to 350 degrees F (175 degrees C).

Cook beef in a large skillet over medium-high heat until crumbly and brown, 8 to 10 minutes. Stir spaghetti sauce into beef. Reduce heat and simmer.

Meanwhile, bring a large pot of lightly salted water to a boil. Stir in spaghetti; cook until al dente, 8 to 10 minutes. Drain.

Add spaghetti to meat mixture; mix well. Transfer to a 9x13-inch dish. Top with Cheddar cheese.

Bake in the preheated oven until heated through and cheese is bubbly, about 30 minutes.