Katie Holmes: My Marriage To Tom Cruise was Kaput in 2011

TMZ has learned ... Katie Holmes says her marriage to Tom Cruise was "irretrievably" broken at least 6 months prior to her filing for divorce ... this according to divorce documents filed in New York.

Sources connected to Tom tell TMZ ... Katie's contention is baffling, because he had "no idea" she was about to file for divorce. As the sources told us last week, Tom was "blindsided" by the filing.

Indeed, take a look at the pic (below) of Tom and Katie strolling the streets of Iceland hand-in-hand a little more than 2 weeks ago.

But wait ... there's more.

We've also learned ... Katie claims in her divorce documents that both she and Tom have been residents of New York for "at least 2 years." Katie, who filed in NYC, must establish legal residency in NY in order for the court to have jurisdiction -- something she wants because New York courts are more likely to grant sole custody of Suri.

No doubt ... Tom -- who shared a home with Katie in Beverly Hills for years -- will fight the residency claim tooth and nail.