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.
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.
[2] When Carcoar was abolished in 1894, he switched to Cowra, winning the seat in 1894,[3] and holding it at the 1895 election,[4] Donnelly died in Sydney in 1896 (aged 62–63).