He was born in Killalbely in County Meath to farmer Bernard McGarry and Mary Loughlin.
He tried his luck on the Gundagai goldfields and spent time in the northern sugar district before returning to settle in Sydney around 1900.
A supporter of military conscription, he left the party in the 1916 split and won re-election in 1917 as a Nationalist.
In 1920, with the introduction of proportional representation, he was denied preselection for the new multi-member Murrumbidgee and was defeated as an independent Nationalist.
He is believed to have made some money as a land dealer after his defeat, but he died impoverished in Hunters Hill in 1930.