The 32-year-old actor has been married to his "Step Up" co-star Dewan since 2009 and now the couple are expecting their first child in 2013, reported People magazine.
Tatum has already said that he will take a break from acting next year.
The star previously said of his desire to start a family.
"The first number that pops into my head is three, but I just want one to be healthy and then we'll see where we go after that," he had said.
Tatum was named the Sexiest Man Alive earlier this year.