Place the potatoes into a large pot and cover with salted water. Bring to a boil over high heat, then reduce heat to medium-low, cover, and simmer until tender, about 20 minutes.
Drain thoroughly.
Meanwhile, place the bacon in a large, deep skillet, and cook over medium-high heat, turning occasionally, until evenly browned, about 10 minutes.
Drain the bacon slices on a paper towel-lined plate, then crumble. Set the bacon aside.
Preheat an oven to 350 degrees F (175 degrees C). Grease an 8-inch square baking dish.
Combine the potatoes, Cheddar cheese, relish, onion, and olives in a large bowl. Stir in the mayonnaise, celery salt, and black pepper.
Transfer the mixture into the prepared baking dish, and sprinkle with bacon.
Bake in the preheated oven until the potatoes are browned and the cheese is melted, about 45 minutes.
