The fastest and easiest way to reheat bacon is by popping it in a microwave for 20 to 60 seconds. The downside to it, however, is that it does not maintain its crispiness, smell, and texture, and space is only limited to a few strips.
Another method of reheating bacon is with a non-stick skillet, although it will need extra time and cleanup compared to the microwave. Just preheat the skillet on the stove over medium heat for a few minutes and throw in the leftover bacon until it sizzles.
When it comes to reheating a large amount of bacon, the oven is the recommended way. Simply preheat the oven to 350 degrees F, line the bacon on a baking sheet, cover it with aluminum foil, and let it bake for 8 to 10 minutes.