Yes! You can absolutely make deviled eggs in advance. I usually hard boil a large batch of eggs to make it easy (up to a week in advance). You can cut the eggs in half and place them in an airtight container or a tray (covered in plastic wrap) in a single layer, in the fridge. Then, you can prepare the filling and also place them in the fridge (up to two days in advance). Then, when it's time to serve, just remove the eggs and filling and pipe them!