On Monday, Roberts' August: Osage County co-star, Meryl Streep, also spoke out against Weinstein.
"The disgraceful news about Harvey Weinstein has appalled those of us whose work he championed, and those whose good and worthy causes he supported," Streep said in a statement to The Huffington Post.
She also stressed that not everybody who worked with him was aware of the multiple sexual harassment allegations against him.
"One thing can be clarified. Not everybody knew," Streep said. "Harvey supported the work fiercely, was exasperating but respectful with me in our working relationship, and with many others with whom he worked professionally. I didn’t know about these other offenses: I did not know about his financial settlements with actresses and colleagues; I did not know about his having meetings in his hotel room, his bathroom, or other inappropriate, coercive acts."