The child, due in January, is the former boxing champion's second with wife Lakiha Spicer Tyson. The couple has a 21-month-old daughter, Milan.
"They are very happy and everyone is doing great," their rep told the site.
The news comes more than year after the death of Tyson's 4-year-old daughter, Exodus. She was found unconscious and wrapped in a cord hanging from a treadmill. Tyson and Spicer wed two weeks after Exodus' death in a private ceremony.