The 'Dawson's Creek' star smiled as she was hounded by photographers on the set of 'Project Runway: All Stars' in New York.
And although her fierce group of bodyguards tried to hide her left hand, it was clear that Katie had taken off her wedding ring.
The 33-year-old actress gave a meek grin as she made her way through the paps in NYC in a blue and black shirt dress.
And her left hand - which was tightly clutched by one of her new security people - was clearly showing a naked wedding finger.
Insiders on the set of the movie, in which Katie is making a guest appearance, said she did a wonderful job despite what was going on in her private life.
One said: "She was engaged, articulate and wonderful".
Meanwhile her estranged husband Tom Cruise, who is today celebrating his 50th birthday, was miles away in Iceland where he is getting on with his own career, filming 'Oblivion'.
Katie Holmes filed for divorce from the Hollywood actor on Friday, citing "irreconcilable differences".
It is believe she was worried their daughter Suri would be sent away to an extreme Scientology camp.
The six-year-old was apparently being prepped for Sea Organisation - an association of Scientologists.
And last night it emerged that little Suri had already faced an inquisition of 99 sinister questions at a Scientology boot camp.
Apparently Katie, who was a raised a Catholic, had been stalked for weeks by Scientologists in the run-up to the announcement about the divorce.
Yesterday it emerged that the actress had sacked her publicist and reverted back to the one she was using before she married Tom.
Katie wants sole custody of Suri - something she is more likely to get in the courts of New York.
So she is claiming that her marital home with Tom has been in Manhatten for two years. She has been careful to be pictured there every day in the run-up to the announcement.