Preheat the oven to 375 degrees. Bring a large pot of salted water to a boil and cook the lasagna noodles according to package directions until al dente. Drain and set aside.
Spread 1/2 cup marinara sauce in the bottom of a 9x13 baking dish. Arrange 4 noodles in a single layer over the sauce.
Scatter half of the crumbled meatloaf evenly over the noodles. Dollop half of the ricotta cheese across the meatloaf and sprinkle with 1/2 cup mozzarella.
Repeat the layers with the remaining noodles, meatloaf, ricotta, and another 1/2 cup mozzarella. Pour the remaining marinara sauce over the top and finish with the rest of the mozzarella and the Parmesan.
Cover the dish with foil and bake for 25 minutes. Remove the foil and bake for 10 more minutes until the cheese is bubbly and lightly browned. Let the lasagna rest for 5 minutes before slicing.