Walter Oswald Watt, OBE (11 February 1878 – 21 May 1921) was an Australian aviator and businessman. The son of a Scottish-Australian merchant and politician, he was born in England and moved to Sydney when he was one year old, returning to Britain at the age of eleven for education at Bristol and Cambridge. In 1900 he went back to Australia and enlisted in the Militia, before acquiring cattle stations in New South Wales and Queensland. He was also a partner in the family shipping firm.
The first Australian to qualify for a Royal Aero Club flying certificate, in 1911, Watt joined the French Foreign Legion as a pilot on the outbreak of World War I. He transferred to the Australian Flying Corps (AFC) in 1916, quickly progressing from flight commander with No. 1 Squadron in Egypt to commanding officer of No. 2 Squadron on the Western Front. By February 1918, he had been promoted to lieutenant colonel and taken command of the AFC's 1st Training Wing in England.
A recipient of France's Legion of Honour and Croix de Guerre, and twice mentioned in despatches during the war, Watt was appointed an Officer of the Order of the British Empire in 1919. He left the military to pursue business interests in Australia, and was lauded for his generosity to other returned airmen. In 1921, at the age of forty-three, he died by accidental drowning at Bilgola Beach, New South Wales. He is commemorated by the Oswald Watt Gold Medal for outstanding achievement in Australian aviation, and the Oswald Watt Fund at the University of Sydney.