According to Star magazine, the former Dawson's Creek actress - who announced her split from Cruise last month - has reached out to Bullock, who divorced hubby Jesse James in 2010.
A source told the publication: "They met years ago through their mutual friend, Keanu Reeves, and Sandra knows all too well about being in a bad marriage – she’s been a real comfort to Katie."
The magazine also reports that Katie decided she wanted to divorce Tom last Christmas, with a friend adding that she "started talking very quietly to her lawyer."
Over the weekend, TMZ claimed that Cruise and Holmes are hoping to settle their divorce out of court, and have apparently called a temporary truce when it comes to legal proceedings.
People magazine has since added that if they can agree on what happens to their properties, child support, visitation and custody of their six-year old daughter Suri, they will not need to appear in court.
A source said that Cruise "doesn’t want his family dragged through the mud – they love their daughter."
However, reports now suggest that Holmes is 'dead-set' on retaining full custody of Suri, with an insider telling Us Weekly: "She is dead-set on keeping custody of Suri. Katie is not going to compromise on certain issues, all regarding Suri."
Another source stated: "This is about protecting her daughter."