Sir Austin Chapman (10 July 1864 - 12 January 1926), Australian politician, was a member of several early federal ministries. He was born in Bowral , New South Wales, and was apprenticed as a saddler at an early age. In about 1884 he went into business as a publican, storekeeper and auctioneer in Queanbeyan, and later became an investor and company director. In 1894 he was elected to the New South Wales Legislative Assembly as MLA for Braidwood. Like most politicians from the southern border regions of New South Wales, he was an active supporter of federation of the Australian colonies.

In 1901 Chapman was elected to the first House of Representatives as MP for the Division of Eden-Monaro. A Protectionist, he was Minister for Defence in the first ministry of Alfred Deakin (1903-05), Postmaster-General in the second Deakin ministry (1905-08), and Minister for Trade and Customs from 1907-08. After a long period on the backbench, he was Minister for Health in the Bruce government (1923-24). He was made KCMG in 1924.

Chapman's most important contribution was his influence on the choice of the site of Australia's national capital, Canberra. He lobbied hard for the site on the Molonglo River near Queanbeyan, in his electorate. The success of his lobbying benefited many of his friends who owned land in the area, and also greatly boosted trade in Queanbeyan, the nearest town to the site. He was still MP for Eden-Monaro at the time of his death in 1926.