Ampullaviridae is a family of viruses that infect archaea of the genus Acidianus. Only one genus in this family has been described, Ampullavirus, which contains one species, Acidianus bottle-shaped virus. The name of the family and genus is derived from the Latin word for bottle, ampulla, due to the virions having the shape of a bottle. The family was first described during an investigation of the microbial flora of hot springs in Italy.