The 1909 Brighton state by-election was held on 8 October 1909 to elect the next member for Brighton in the Victorian Legislative Assembly, following the death of incumbent MP and former premier Thomas Bent. Bent, who served as premier from February 1904 until January 1909, died on 17 September 1909 at his home in Bay Street, Brighton. He had been unopposed at the previous election in 1908.