Austin Diamond (10 July 1874 – 5 August 1966) was a cricketer who played first-class cricket for New South Wales from 1899 to 1918, including 14 matches as captain. A disciplined and determined batsman, Diamond had his best season in 1906-07, when he scored 502 runs at an average of 83.66, including his only double-century, 210 not out against Victoria. Diamond captained the unofficial Australian tour to Fiji, Canada and the USA from May to September 1913. The tour included five first-class matches, as well as many minor matches.