David Owen Sillence AM (born 1944) is an academic and medical geneticist. He is an Emeritus Professor at the University of Sydney, where he was the foundation chair (Professor) of Medical Genetics. An honours graduate of the University of Sydney, he obtained his MD in Medical Genetics from the University of Melbourne 1978 in bone dysplasia. Sillence created the standard four-type system of osteogenesis imperfecta in 1979. It enabled progress into the molecular causes of the disorder and collagen mutations.