The Rock of Ages star and his actress wife – who have been married for five years – have confirmed they have split, with Katie’s attorney Jonathan Wolfe saying she wants to do what is best for their six-year-old daughter Suri.
Wolfe said: “This is a personal and private matter for Katie and her family. Katie’s primary concern remains, as it always has been, her daughter’s best interest.”
A source told RadarOnline.com: “After five years of this Katie really felt like she was going crazy and that she was actually turning into the robot that the press had always made her out to be.
"Katie... used to be spunky and feisty. She changed so much when she was with Tom, she became downtrodden and insipid."
The source added that Katie "lost the starstruck goggles she had been wearing” and knew having an equal say in what's best for Suri "would be impossible if she remained Mrs Tom Cruise."
It is not known if divorce papers have yet been filed in court.
Tom – who has been married twice before to Nicole Kidman and Mimi Rogers – wed the former Dawson’s Creek actress in an Italian castle in November 2006.
Unlike his divorce from Nicole, Tom has not had a chance to control the spread of his divorce news and is believed to have been blind-sighted by it.
His representative said in a statement: “Kate has filed for divorce and Tom is deeply saddened and is concentrating on his three children. Please allow them their privacy.”
Tom recently gushed about his wife saying he loved her “creativity” and claiming their relationship was “very special”.
He said: “She is an extraordinary person, and if you spent five minutes with her, you'd see it.
"Everything she does, she does with this beautiful creativity. She has a voice and warmth as an artist, as a mother. She's funny and charming, and when she walks into the room, I just feel better.
"I'm a romantic. I like doing things like creating romantic dinners, and she enjoys that.
"I don't know what to say - I'm just happy, and I have been since the moment I met her. What we have is very special."
TMZ reports that Katie has asked for legal custody, primary residential custody and a 'suitable amount' of child support for daughter Suri from her husband.The couple are said to be worth about $275 million combined, mostly due to Tom's blockbuster box office success, The Daily Mail reports.