He caught the acting bug when The Young Elizabethan Players performed Hamlet (featuring Kirrily Nolan as Ophelia) at his Charters Towers high school.
[2] Together with Jonathan Biggins and Phillip Scott, Forsythe was a creator, writer, and performer of Three Men and a Baby Grand which started at the Tilbury Hotel in Woolloomooloo.
Forsythe appeared in the films Stone, Caddie, Newsfront, Annie's Coming Out, Ginger Meggs, Burke & Wills, Travelling North and Billy's Holiday.
He has also made guest appearances on a number of popular television series, including Cop Shop, A Country Practice, G.P., BackBerner, All Saints, and Packed to the Rafters.
Forsythe is credited with singing the theme song for the ABC's long-running Sunday morning radio program, Australia All Over, hosted by Ian McNamara.