He will succeed Bishop Geoffrey Mayne who turns 75 next month and whose resignation was accepted by the Pope.
Monsignor Davis will be the first Australian military bishop to have served in the defense forces before being ordained a priest.
He was born in Townsville in 1945 and grew up in Perth, where he was educated by the Christian Brothers.
From 1962 to 1964 he served in the Royal Australian Navy, before entering the seminary. He was ordained a priest in 1971 and appointed part-time chaplain for the Australian Army, followed by parish appointments in the Perth Archdiocese.
Among other duties, he has worked as chancellor of the Military Ordinariate, and been an assistant priest at St. Christopher’s Cathedral, Canberra.