Yes, letters written to Santa are delivered to the North Pole on Christmas Eve. Many children write letters to Santa expressing their wishes for toys and gifts, and these letters are collected and sorted by the elves in Santa's workshop. On Christmas Eve, Santa reads the letters and prepares the toys and gifts to be delivered to the children on Christmas morning. The post office plays a crucial role in delivering letters to Santa, as they often receive a large volume of mail addressed to Santa around the holiday season.