David Simmons was born in Perth to parrents from the Nyoongah language group of far south Western Australia. Simmons's brother is Clarrie Issacs, a well-known Elder in the Perth region, who was a passionate advocate for Aboriginal people's rights. Simmons went to school at Parkerville and he and his siblings spent a lot of time hiding from the Native Welfare. Simmons was educated until the age of fourteen when he began working in a timber mill and a nursery before working for Humes and the Water Authority. In 1967 he went north to work as a earthworks contractor and returned home to work for Nylex. Simmons also worked as a truck driver and pool manager, among other jobs, before being recruited into the public service as a field officer in the Aboriginal Employment and Training Branch after completing TAFE training. Simmons has also worked as coordinator of the Community Development Employment Program (CDEP) in Roebourne.