Jennie Garth & Peter Facinelli -- Divorce Final ... Nicest Divorce Ever

Former "90210" star Jennie Garth is officially a single woman ... because her divorce from "Twilight" actor Peter Facinelli has been finalized -- and it's quite possibly the most amicable and novel divorce of all time.

As we reported, Garth and Facinelli pulled the plug on their marriage in 2012 after 11 years together. They have three daughters -- 15-year-old Luca Bella, 10-year-old Lola Ray, and 6-year-old Fiona Eve.

The divorce order was officially signed Tuesday -- but the real story ... Garth and Facinelli still totally trust each other -- especially in the money department.

The two have each declined spousal support. As for the children, they're doing something pretty novel. Jennie and Peter are funding a joint bank account for the care and education of their children. Both parents will deposit money in equal amounts. Each has full access to the accounts.

They have also agreed to share 50/50 custody of their daughters and insist they don't need a formal custody arrangement -- unheard of in Hollywood.