Jarratt was born and grew up in Wongawilli, a small rural town near Wollongong, New South Wales, and later in the Snowy Mountains area. Jarratt's father was a coal miner, and later a concreter working on the Snowy Mountains Hydro-Electric Scheme. Jarratt comes from a family of Irish Catholic descent; however, his patrilineal ancestor George Jarratt, born 1833, came from Croxton in Cambridgeshire, England. George's son John married Mary Kelly from Ireland.