Born in Galway, Ireland in 1817, nothing is known of his life until he arrived in Western Australia on board the Trusty in about 1842. Initially he lived at Australind, then moved to Hotham River to manage William Burges" station there. Pastoralism
In 1850, Davis joined a group of pastoralists including Major Logue, William and Lockier Burges, and Thomas and Kenneth Brown, in overlanding stock from York to Greenough.
From 1852 he was partner in a lease of Glengarry, and the following year he settled at Tibradden Station.
Western Australian Legislative Council
On 12 March 1884, John Davis was elected to the Western Australian Legislative Council seat of Geraldton in a by-election. He held the seat until 27 October 1884.
He died at Tibradden on 30 September 1893. In 1858 he became a Justice of the Peace.