Whoopi Goldberg has joined the cast of 'Till'.

The 65-year-old actress will star as Emmett Till's grandmother Alma Carthan in the upcoming movie, which centres on the story of Till's mother and her fight for justice.

Danielle Deadwyler will star in the film as Mamie Till-Mobley, who seeks justice for her son after he's killed by a white mob.

Whoopi is also producing the project alongside Keith Beauchamp, Barbara Broccoli, Thomas K. Levine, Michael JP Reilly and Frederick Zollo.

The upcoming project is being directed and written by Chinonye Chukwu, and production work is poised to start later this year.

Whoopi told Variety: "We have waited a very long time to bring this historically necessary important film to people. And as we watch the repression of American History when it comes to people of colour it makes it even that more important. I couldn’t be with better people: Fred, Barbara, Chinonye, Keith, Michael and Danielle."

Whoopi previously starred in the Steven Spielberg-directed film adaptation of Alice Walker's award-winning novel 'The Color Purple'.

The acclaimed movie tells the story of a young African-American girl in the early 20th century, and Whoopi joined the project after writing a letter to the author.

Explaining how she joined the cast, the actress recalled: "I wrote her a letter and said I would do anything, if there was ever going to be anything done with her book. I would play any character. I would play dirt on the floor. I would be a screen door. She wrote back and said she knew who I was, she had seen my show in San Francisco, she had already mentioned me to Spielberg.

"Then Steven asked me to do my show before a few of his friends in Los Angeles. A few of his friends! Do you know who his friends are? There were 80 people in the room. Michael Jackson was there."