The actress has moved out of the New York apartment she shared with Tom, taking the couple's six-year-old daughter Suri with her.
On June 28 – the morning she filed for divorce – the 33-year-old was spotted moving bags to another apartment in the Big Apple (below).
Their new place is near to some of the mother-daughter team's favourite places, including a gymnastics studio where Suri takes classes.
Meanwhile Tom, who turns 50 on Tuesday, is still in Iceland where he's filming Oblivion.
The Hollywood star said he was "deeply saddened" by Katie's moves to end the marriage.
Katie has said that her daughter is her "primary concern", and TMZ reports that the star is seeking sole custody.
The actress is also believed to be asking for a division of property in the divorce documents, although it's thought she signed a pre-nuptial agreement under Californian law.
The reported terms of the document stipulate that Katie would be entitled to $3 million for every year of marriage, plus their $35 million home in Beverly Hills.
Their estimated combined worth is upwards of $275 million, largely down to Tom's box office success.
Katie's lawyer confirmed on Friday that the couple are divorcing but called it a private matter for the family.
She has assembled an expert legal team to help her finalise the divorce, including Allan Mayefsky, who regularly helps the ex wives of wall street millionaires reach multi-million settlements.
He has a reputation as a shrewd operator who has a habit of airing the grievances of his clients in front of the media.
Katie has also employed New Jersey attorney Jonathan Wolfe, who is an expert in what's known as 'business evaluation' – or in layman's terms, finding hidden money.
The fact the brunette beauty has decided to remain in New York – where courts tend to favour giving sole custody to one parent, rather than joint custody as they do in California – may also be significant.
Tom wed Dawson's Creek star Katie in 2006 in an Italian castle after publicly declaring his love on Oprah Winfrey's TV show, famously jumping on her couch in excitement.
The Rock of Ages star was previously married to Mimi Rogers and Nicole Kidman, with whom he has two children – Connor and Isabella.
Tom's representative said: "Kate has filed for divorce and Tom is deeply saddened and is concentrating on his three children.
"Please allow them their privacy to work this out."
Tom and Katie's $275 million fortune
- Nine-bedroom home in Colorado which couple bought for $30 million dollars in 2006, to which they added a $10 million bunker
- Lavish $15 million apartment in New York's Manhattan district
- Six-bedroom, $5 million home in Sussex, England, boasting an indoor swimming pool, underground garage, sports pavilion, high tech security system and staff cottage
- Villa in Lake Como, Italy bought from friend George Clooney for almost $7 million
- A Gulfstream IV-SP bought as a wedding present for Katie
- Luxurious Aviat – Pitts S-2B airplane and a North American Aviation P-51 Mustang, emblazoned with 'Kiss Me, Kate'
- Fleet of sports cars, including a Porsche 911 and a 16-cylinder V8