Demi Moore is finally filing divorce papers, 16 months after splitting up with Ashton Kutcher, Page Six can exclusively reveal.

An insider tells us she tired of trying to reach a confidential settlement with Kutcher, and that the couple’s divorce could go to a trial.

“Ashton made a lot of money after marrying Demi — a lot more than she made — but despite him becoming just as famous through her, he believes he doesn’t owe her that much,” the source said,” adding of Demi: “She has had enough.”

Moore’s lawyers could file paperwork in Los Angeles as early as today, we hear. Kutcher filed divorce papers in December, a year after the couple split, but this would be the first time Moore responds. She’d been hoping to quietly negotiate a settlement and then file the papers once an agreement was reached.

But negotiations got bogged down, and, “Ashton has been very difficult during the talks,” the insider said. “You could even say he has been hostile.” Kutcher is the highest-paid actor on TV, pulling in $24 million last year for “Two and a Half Men,” and he’s also become a savvy investor in various tech start-ups.

“After over a year of attempting to reach a settlement, Demi is definitely ready to move on,” the source said of her decision to file. “It’s hoped lawyers for both sides can reach a settlement this spring, otherwise the divorce will go into litigation and trial.”

Kutcher’s being repped by LA celebrity lawyer Laura Wasser, while Moore’s retained powerhouse New York attorney William Beslow, who recently helped Linda Evangelista land a generous settlement in a child support battle with mogul François-Henri Pinault.

Since Moore, 50, announced she was ending her six-year marriage to Kutcher, now 35, in 2011, speculation has run rampant as to why they haven’t reached a settlement.

Demi was in New York on Monday night with friends. The source added, “She is healthy and happy, and just wants to move on with her life.”