William Ernest Cooke (25 July 1863 – 7 November 1947), generally referred to as W. Ernest Cooke or informally Ernest Cooke, was an Australian astronomer, credited with a number of important scientific breakthroughs and improved methodologies in astronomical observations and star cataloguing. He was the first Western Australian Government Astronomer and established the Perth Observatory as one of the best equipped and productive establishments of its type in Australia.