Michael Dunn (October 20, 1934 – August 30, 1973) was an American actor and singer. He inspired a number of actors that were smaller and shorter than most "average" people, including Zelda Rubinstein, Mark Povinelli, and Ricardo Gil.
Dunn suffered from medical dwarfism, a result of spondyloepiphyseal dysplasia (SED, subtype unknown), a genetic defect of cartilage production caused by a mutation in the COL2A1 (type II collagen) gene. This disorder, classified as a skeletal dysplasia, caused distorted development of his limbs, spine, and ribcage and led to early, widespread osteoarthritis and constricted lung growth. As an adult, he stood 3' 10" and weighed about 78 pounds (117 cm, 35 kg). During Dunn's lifetime, his condition was described by the nonspecific term "progressive chondrodystrophy," or alternatively as "achondroplasia", a term that now refers specifically to a skeletal dysplasia caused by a defect in the gene for fibroblast growth factor receptor 3.