The Iron Man star took to Twitter and Facebook on Wednesday to announce that he and his wife of nine years, Susan, were expecting their second child together. Downey has a 20-year-old son, Indio, from his first marriage to Deborah Falconer.
"Yo. Susan. Me. Baby. Girl. November. Scorpio?" he tweeted.
Susan gave birth to the couple's first child, Exton Elias, in 2012.
"Um. I don't know if it's a 'man's world,' but I'm certain women run it," Downey added in a Facebook post. "Susan and I are therefore delighted to announce we are expecting a baby. Girl. November."
Downey's oldest son, Indio, was arrested last month on cocaine charges. Downey, who has struggled with addiction, said in a statement that the family was "we're all determined to rally behind him and help him become the man he's capable of being."
Yo. Susan. Me. Baby. Girl. November. Scorpio?— Robert Downey Jr (@RobertDowneyJr) July 9, 2014
Celebrity Families of 2014 [PHOTOS]