Her representative said on Monday that she gave birth to a boy.
The 27-year-old actress is married to British actor Jamie Bell. They were married last year.
The rep adds that "parents and baby are all doing well." No more details were provided.
Wood credits include The Wrestler, Thirteen and HBO's True Blood. She earned Golden Globe and Emmy nominations for her supporting role in Mildred Pierce.
Bell, also 27, is best known for his roles in the films Billy Elliot, King Kong and The Adventures of Tintin.