This 5-ingredient oven baked tuna lasagna is the kind of weeknight dinner that feels almost too easy for how comforting it turns out. It leans on pantry staples, skips the noodle boiling step, and uses undrained canned tuna so everything bakes up tender and flavorful right in the dish. If you are juggling work, errands, and the usual evening rush, this is a practical casserole-style meal that still comes out creamy, hearty, and family-friendly.

Serve this tuna lasagna with a crisp green salad, simple steamed broccoli, or roasted green beans to balance the richness. A slice of garlic bread or warm crusty bread is great for catching the extra sauce, and if you want a lighter finish, fresh lemon wedges on the side add a nice bright contrast to the creamy baked pasta.

5-Ingredient Oven Baked Tuna Lasagna

Servings: 6

Finished tuna lasagna plated on a dinner plate
Finished tuna lasagna plated on a dinner plate

Ingredients

12 dry uncooked lasagna noodles

2 cans tuna in water, undrained, 5 ounces each
1 jar marinara sauce, 24 ounces
1 container ricotta cheese, 15 ounces
2 cups shredded mozzarella cheese

Directions

1. Preheat the oven to 375°F and lightly coat a 9x13-inch casserole dish with nonstick spray or a thin layer of oil.

2. Spread a thin layer of marinara sauce in the bottom of the dish. Arrange 3 lasagna noodles over the sauce, breaking them as needed to fit.

3. Spoon over one-third of the ricotta, one-third of the undrained tuna, and one-third of the mozzarella. Top with more marinara sauce. Repeat the layers two more times, finishing with marinara and the last of the mozzarella on top.

4. Cover the dish tightly with foil and bake for 45 minutes. Remove the foil and bake for 15 to 20 minutes more, until the noodles are tender and the cheese is melted and lightly golden.

5. Let the lasagna rest for 10 to 15 minutes before slicing and serving so the layers can set up and cut more cleanly.

Variations & Tips

Add a little seasoning: If you want to build a bit more flavor without changing the simple formula, add black pepper, Italian seasoning, garlic powder, or a pinch of red pepper flakes between the layers.

Make it creamier: For a softer, richer texture, stir the ricotta before layering so it spreads more easily, or mix it with a small spoonful of marinara first.

Check noodle tenderness: Because oven temperatures and sauce thickness can vary, test the center noodles before pulling the dish out for good. If they still feel firm, cover and bake for another 10 minutes.

Try a veggie addition: A layer of well-drained spinach or finely chopped sautéed mushrooms works nicely here, but keep extras modest so the noodles still absorb enough moisture to cook properly.

Meal prep tip: This is a great make-ahead dinner for a busy week. Assemble the casserole earlier in the day, refrigerate it covered, and add a few extra minutes to the baking time if it goes into the oven cold.