John Ernest McDonald was born in Hobart on 28 Sep 1873, the eldest son of John James McDonald (born 13 Mar 1850) and Sarah Ann Self (born 28 Jun 1855), who were married on 19 Dec 1872 in Hobart. John had six brothers and sisters: Frederick Charles, born 12 May 1876; Florence Elizabeth, 5 July 1879; Douglas Frank, 12 Oct 1881; Ruby Eveline, 26 Feb 1883; Darcy Gordon, 24 April 1885; and Lindley Winfield, 14 Aug 1887.
John's father was the superintendent of the railway telegraph in Launceston at the time of the Tasmanian Exhibition in 1891-92. John and his brother Frederick were both in the Exhibition Choir.
John Ernest McDonald married Josephine Caroline Donovan on 23 Dec 1895 in Hobart. In 1903 they were living in New Town. John worked as a clerk in Hobart, and later as a labourer at Bushy Park. He drowned in the Derwent River on 15 Dec 1945 aged 72. At 8am a waterside worker heard someone calling out near the Elizabeth Street Wharf. The coroner could not determine how John had entered the water, therefore he recorded an open finding. John Ernest MacDonald was buried on 18 Dec 1945 at the Cornelian Bay Cemetery.