Forrest was born in
Bunbury, Western Australia, to Mary (née Parker) and
David Forrest. His father and two uncles (
Alexander and
John) were also members of parliament, with John being Western Australia's first
premier. Forrest lived at
Minderoo Station for periods as a child, and was later sent to
Perth to be educated, attending
Hale School and
Guildford Grammar School. After leaving school, he worked for family businesses as a
jackaroo at Cubbine Station,
bookkeeper in Perth, and station overseer of Minderoo. Forrest eventually became managing director of the
holding company for the Minderoo and
Wyloo leases, and also served on the executive of the
Pastoralists and Graziers Association. He became a
justice of the peace in 1916. ==Family==