Moore will play the iconic feminist Gloria Steinem, while Roberts will be play a lie-detector expert. Brody will play "Deep Throat" male lead Harry Reems.
Lovelace's role in the notorious 1972 hardcore-porn movie made her one of the best-known figures in adult entertainment.
As previously announced, Amanda Seyfried will play the title role in the movie, which Millennium Films is making with the cooperation of Lovelace's estate.
Peter Sarsgaard will portray Lovelace’s husband, Chuck Traynor, and James Franco will play Hugh Hefner.
Other castmembers include Hank Azaria, Bobby Cannavale, Chris Noth, Robert Patrick, Wes Bentley, Sharon Stone and Juno Temple.
"Lovelace" is directed by Rob Epstein and Jeffrey Friedman (“Bowl,” “The Celluloid Closet”). The screenplay was written by Andy Bellin (“Trust”).
The film has an estimated budget of $10 million and is currently filming. A release date has not been set.
"Lovelace" is being produced by Heidi Jo Markel, Laura Rister, Jason Weinberg and Jim Young. Boaz Davidson, Danny Dimbort, Mark Gill, W. Merritt Johnson, Avi Lerner, Trevor Short and John Thompson are executive producing.
"Lovelace" is one of two Lovelace projects now under way. Writer-director Matthew Wilder's "Inferno: A Linda Lovestace Story," based on Lovelace's autobiography, is due in 2013. Malin Akerman will star in that movie.