Janelle Monae has been cast as Dorothy Pitman Hughes in the forthcoming Gloria Steinem biopic.

The 33-year-old actress-and-singer joins Julianne Moore and Alicia Vikander, who both portray the titular women's rights activist at various stages in her life, for the adaptation of the late protestor's 2015 feminist memoir, 'My Life on the Road'.

'The Glorias: A Life on the Road' is directed by Julie Taymor and Sarah Ruhl penned the screenplay.

The plot is set to evolve from ''a low-key spokeswoman of a movement to an electrifying symbol of equality, with a focus on the encounters on their path that have helped shape them.''

Steinem became a famous feminist in the 1960s and 1970s, and founded the first US women's rights journal in 1971.

Bette Midler is also set to play the role of Bella Abzug, who along with Steinem and her peers launched the the National Women's Political Caucus.

As as well as being a Grammy-nominated music star - who released the much-lauded album 'Dirty Computer' this year - Monae has had a successful career in film.

She launched her big screen career with 2016's 'Moonlight' and rose to critical acclaim in 'Hidden Figures', which saw her awarded the Hollywood Spotlight Award at the Hollywood Film Awards.

Monae's next big screen role is this month's 'Welcome to Marwen', which she stars as GI Julie in alongside Steve Carrell's Mark Hogancamp.