The 37-year-old Oscar winner, who already has two kids daughter Mia and son Joe from her previous relationships, announced in June that she and husband Ned Rocknroll are expecting their first child, reported People Magazine.
"I have admiration for mothers everywhere. Being a parent turns you inside out. It completely transforms your life and, of course, your children are your absolute everything," Winslet said.
"The Reader" actress debuted her baby bump at the Toronto International Film Festival where she was promoting her new film "Labor Day" in which she plays a divorced, single mother.