Preheat oven to 350 degrees F (175 degrees C). Lightly grease a medium baking dish.
In a skillet over medium heat, cook the ground beef and onion until the beef is evenly brown and the onion is tender. Remove from heat.
Layer 1/2 the potatoes in the bottom of the prepared baking dish, and cover with 1/2 the beef and onion mixture. Spread 1/2 the kidney beans and 1/2 their liquid over the beef and onion, and season with salt and pepper. Repeat the layers, and cover with the tomato soup. Top with the bacon.
Cover and bake 1 hour in the preheated oven. Remove cover and continue baking 1 hour, or until the bacon is crisp and the potatoes are tender.