Fake Ophelia, a large collage on canvas by Steven Campbell - a leading figure in the high-profile group of graduates known collectively as The New Glasgow Boys - will be hung in the institution’s library.
The Gregory’s Girl director and his partner Moira Wylie gifted the work made in 1991 by Campbell, who died at the age of 54 in 2007.
It is formed of paint, textiles, string, wallpaper and paper cut work.
Campbell went to the GSA as a mature student, graduating in 1982 with a Fulbright Scholarship which he used to travel to New York.
He returned to live in Glasgow in 1986 and emerged in the group of Scottish figurative painters which also consisted of fellow GSA alumni Ken Currie, Peter Howson and Adrian Wiszniewski.
He met Forsyth in the 1980s and they became fishing buddies.
Alison Stevenson, head of learning resources at the GSA, said: “We are grateful to Bill and Moira for this generous donation to the GSA’s archives and collections.
“Steven was an incredibly talented artist whose life was cut tragically short. We are delighted to be able to add Fake Ophelia to our rich collection of works by GSA graduates.”