Holmes' pregnancy was reported Wednesday by People magazine. The couple have been dating since April and became engaged in June.
"Tom and Katie are very excited, and the entire family is very excited," Lee Anne DeVette, Cruise's spokeswoman, told People.
Did that include his ex-wife, Nicole Kidman and their kids, Isabella, 12, and Conner, 10?
"I asked his sister and publicist (DeVette) how each individual was taking it," CBS News Early Show entertainment contributor and People magazine senior editor Jess Cagle said. "She didn't want to single anybody out. She said the entire family is very excited about it."
Devette added that Holmes, 26, "has never felt better." It would be her first child.
Cruise, 43, is now shooting "Mission" Impossible 3." In a June interview promoting his summer blockbuster "War of the Worlds," Cagle asked the actor if he wanted more children.
Cruise replied: "I love children. I've always wanted to be a father, always. As far back as I could remember, I couldn't wait to have kids. I always loved kids, so it's something Kate and I will talk about …That's always a thing; we'll see. Anything is possible."
After Cruise and Holmes went public with their relationship in April, smooching and posing for photographers in Rome, many doubted the romance — the words "publicity stunt" have rained down on the couple like an alien invasion.
Skeptics may still decry the romance, but it became more difficult to doubt the relationship after a ring became involved.
"Obviously this is — has been very, very fast. It was a surprise to a lot of people, but I think that people who were that cynical about the relationship sort of have egg on their face now," Cagle said.