Sir Richard Olaf Winstedt KBE CMG (2 August 1878 – 2 June 1966), or more commonly R. O. Winstedt, was an English Orientalist and colonial administrator with expertise in British Malaya.
Winstedt was born in Oxford and educated at Magdalen College School and New College, Oxford, from which he received an MA. His brother was Eric Otto Winstedt, a Latinist and .
In 1902 he became a cadet in the Federated Malay States Civil Service, and was posted to Perak where he studied Malay language and culture. In 1913 he was appointed District Officer in Kuala Pilah, and in 1916 appointed to the Education Department. In 1920 he received his DLitt degree from Oxford.
He served as the first President of Raffles College, Singapore, 1928–1931. During his presidency, he also served as acting Secretary to the High Commissioner, 1923, Director of Education for Straits Settlements and Federated Malay States (FMS), as a member of Legislative Council, Straits Settlements, 1924–1931 and as a member of the FMS Federal Council, 1927–1931. He was president of the Malayan Branch of the Royal Asiatic Society in 1927, 1929 and 1931. After a term as General Adviser to Johore, 1931–1935, Winstedt retired from the Malayan Civil Service.