Sir Douglas Ralph Nicholls, KCVO OBE (9 December 1906 – 4 June 1988) was a prominent Aboriginal Australian from the Yorta Yorta people. He was a professional athlete, Churches of Christ pastor and church planter, ceremonial officer and a pioneering campaigner for reconciliation. Nicholls was the first Aboriginal Australian to be knighted when he was appointed Knight Bachelor in 1972 (he was appointed a Knight Commander of the Royal Victorian Order in 1977) and also the first appointed to vice-regal office, serving as Governor of South Australia from 1 December 1976 until his resignation on 30 April 1977 due to poor health.
In December 1942 Nicholls married Gladys Nicholls, the widow of his brother Howard Nicholls (1905–1942); Howard (who had married Gladys in 1927) had died in April 1942 as a result of injuries sustained in a car accident. Gladys already had three children. Douglas Nicholls and Gladys were married for 39 years and raised their combined six children; two sons, Bevan and Ralph, and four daughters, Beryl, Nora, Lilian and Pamela. Lady Gladys Nicholls died in 1981. Nicholls' great grandson Nathan Lovett-Murray also played Australian Rules Football, playing 145 games for Essendon. Nicholls died on 4 June 1988 at Mooroopna. A state funeral was held for him and he was buried in the cemetery at Cummeragunja.