Aldi is a German supermarket chain that operates in several countries around the world, including the United States. In the United States, Aldi stores are typically open on Christmas Eve. The hours may vary by location, so it's best to check the store's website or call ahead to confirm their hours of operation. However, it's important to note that many retail stores may have reduced hours or even be closed on Christmas Eve, so it's always a good idea to plan ahead and shop early if possible.