Robert appeared in over 100 films and television series.
A prolific and acclaimed performer, Forster had over 180 acting credits to his name, and is perhaps best known for his turn as charming bail bondsman Max Cherry in Quentin Tarantino's superb Jackie Brown, which led to an Oscar nomination and a career resurgence.
After starting out his career with roles in such movies as Reflections in a Golden Eye (opposite Elizabeth Taylor and Marlon Brando) and Medium Cool, Forster headlined a pair of short-lived TV series, NBC's Banyon and then ABC's Nakia.
Jackie Brown co-stars Samuel L Jackson and Pam Grier were among those to pay tribute.
Forster's career began way back in 1967 when he was a 26-year-old aspiring actor.
"I had four kids, I took any job I could get", he said in an interview with the Chicago Tribune previous year. He also forged a working relationship with David Lynch, appearing in the director's 2001 hit Mulholland Drive and in the 2017 Twin Peaks revival. He'd lose the supporting actor Oscar that year to Robin Williams for "Good Will Hunting". He said he loved trying out comedy as Tim Allen's father in "Last Man Standing".
"You learn to take whatever jobs there are and make the best you can out of whatever you've got".
He is survived by his four children Bobby, Elizabeth, Kate and Maeghan; his grandchildren Tess, Liam Jack and Olivia; and longtime partner Denise Grayson.