Marshall, who suffered in recent years from Alzheimer's disease, died in a Los Angeles rest home.
The actor appeared in dozens of films and in popular TV series such as "Star Trek" in the 1960s and "The Jeffersons" in the 1980s.
He taught acting workshops at colleges and at the Mufandi Institute in Watts, where he served as director in the 1960s.
On stage, Marshall portrayed singer Paul Robeson and statesman Frederick Douglass, a role he spent 15 years researching. He eventually played the part of the famed abolitionist on television.
Marshall was born in Gary, Ind., and studied acting at the Actors Studio and the Neighborhood Playhouse in New York City after spending several years as an art student at New York University.
He played the Moorish king in "Othello" in Europe and in the United States. The London Sunday Times once hailed him as "the best Othello of our time."
Marshall brought the same dignity to the title role in the 1972 movie, "Blacula" and its sequel, "Scream, Blacula, Scream!" First conceived as a dimwitted count, Marshall modeled the character on the original Count Dracula in Bram Stoker's 19th century novel.