Sir Robert Ross McDonald QC (25 January 1888 – 25 March 1964) was an Australian politician who was a member of the Legislative Assembly of Western Australia from 1933 to 1950, representing the seat of West Perth.
McDonald enlisted as a private in the Australian Imperial Force in 1916, and later served as a lower-level officer with various artillery units in France and Belgium.
On his return to Australia in 1919, McDonald joined the law firm of Robert Thomson Robinson (a fellow Albany native), eventually becoming a partner.
He was a part-time lecturer at the University of Western Australia from 1928 to 1931, and also served as the foundation vice-president of the Australian branch of the International Commission of Jurists.
After leaving politics, he served as a member of the senate of the University of Western Australia (from 1950 to 1961) and as chairman of Royal Perth Hospital (from 1956 to 1960).