Liam Aaron McDermott, weighing 6 pounds, 6 ounces, was born Tuesday at a Los Angeles hospital, CBS reported.
The two were married in a private ceremony in May 2005.
Liam is Spelling's first child. McDermott has a son, Jack, from a previous marriage.
The actress, daughter of the late TV producer Aaron Spelling, reportedly was feuding with her mother, Candy, over her mother's portrayal in the daughter's recent reality show, "So noTORIous."
Candy Spelling said earlier this week that the two are trying to work things out. Tori Spelling's brother, Randy, said the reconciliation arose as their mother was preparing to become a grandmother.
"I think it's a culmination of things. I think when you're family, you have your ups and downs, but hopefully you all come back together," Randy Spelling told "Access Hollywood." "And I'm sure the baby just makes that happen quicker."