Denis Cornelius Joseph Donnelly (1833 – 14 March 1896) was an Irish-born Australian politician. Born at Cork to Cornelius Donnelly and Mary O'Leary, he worked as a miner and a merchant before arriving in Western Australia in 1850. In 1854 he followed the gold rush to Ballarat, and in 1862 moved to Forbes. Although he established a mine at Lucknow, he soon sold it and instead became a flour miller at Peel near Bathurst. On 16 January 1866 he married Ellen Agatha Cummins, with whom he had thirteen children. From around 1878 he kept a store at Cowra. Donnelly died in Sydney in 1896 (aged 62–63).