Dies natalis is Latin for "birthday, anniversary" and may refer to:
The birthday of an individual, or the anniversary of a founding of a temple; see Glossary of ancient Roman religion#dies natalis Dies Natalis Solis Invicti, the "birthday" of the Roman solar deity Sol Invictus on December 25 the annual commemoration of a Christian martyr's death; see Calendar of saints Dies Natalis (cantata), a cantata by Gerald Finzi