"The Normal Heart," set to air on HBO in 2014, tells the story of the dawning of the epidemic in 1980s New York.
Oscar-winner Roberts plays Dr. Emma Brookner, who treats several early patients infected with the HIV virus that causes AIDS. Co-star Mark Ruffalo plays Ned Weeks, an eyewitness to how the disease ravaged the city's gay community.
The film will be directed by "Glee" creator Ryan Murphy and was adapted by the play's author, Larry Kramer, an early advocate for AIDS prevention and care.
"Ryan has assembled an extraordinary cast to bring Larry Kramer's landmark theatrical achievement to the screen for the first time, and we couldn't be more thrilled to bring this important film to HBO," Michael Lombardo, HBO's president of programming, said in a statement.
"The Normal Heart" debuted on stage in 1985 in New York and was revived on Broadway in 2011, winning the Tony Award for best revival.
The movie version was originally envisioned as big screen release before HBO took it up as a television film.
(Reporting by Eric Kelsey; Editing by Will Dunham)