The haloacid dehydrogenase superfamily (HAD superfamily) is a superfamily of enzymes that include phosphatases, phosphonatases, P-type ATPases, beta-phosphoglucomutases, phosphomannomutases, and dehalogenases, and are involved in a variety of cellular processes ranging from amino acid biosynthesis to detoxification.

[1] A HAD domain is found in several distinct proteins including: Human genes encoding proteins that contain this domain include: