Charles Stuart Mein (14 June 1841 – 30 June 1890) was a politician and judge of the Supreme Court of Queensland. Mein was born at Maitland, New South Wales, and attended William Timothy Cape's school, at Darlinghurst until 1857, when he attended the newly opened Sydney Grammar School. He left the school as captain in 1859, and was a colleague of Samuel Griffith from 1860 to 1862 at the University of Sydney, of which he was scholar, and graduated M.A. Mein became private secretary to the Attorney-General of New South Wales, but left for Queensland in 1867, and became a solicitor of the Supreme Court three years later.