Brown Jack (1924–1948) was a Thoroughbred racehorse that raced over hurdles and then on the flat. He was a "stayer" – a horse specialising in longer races. He won the second Cheltenham Champion Hurdle in 1928, but his main claim to fame was winning the Queen Alexandra Stakes – the longest race in the flat racing calendar – for six years running, from 1929 to 1934. His repeated victories made him one of the most popular racehorses in the history of British racing.