The magazine did not indicate in its report when the baby is due or what its gender is.
Simmons, who is the head of the Baby Phat fashion house, also has two young daughters from her marriage to hip-hop mogul Russell Simmons. They separated in 2006 and were officially divorced in 2008 after nearly 10 years of marriage.
Simmons reportedly started dating Hounsou in February 2007.
The actor is best known for his roles in "Blood Diamond," "Gladiator," and "In America."