Daniel Henry Deniehy (1828-1865) was an Australian journalist, orator and politician and early advocate of democracy in colonial New South Wales. He practised law in Goulburn 1854-58, and later in Sydney and Melbourne, where he was active in politics and journalism. He was elected to the NSW Legislative Assembly in 1857 representing Argyle. He was a fierce republican, and is best known for his "Bunyip Aristrocracy" speech delivered to the NSW parliament in 1853.