A manager for the 40-year-old actress, whose film "Half of a Yellow Sun" premiered Sunday at the Toronto International Film Festival, confirmed the news.
"She couldn't be more happy," a source said. "You can barely tell she has a bump and she's been dressing different because of it."
Newton and Parker have two daughters, Ripley, 12, and Nico, 8.
Celebrity Families of 2014 [PHOTOS]