Amy & Matt Roloff -- Little People, Big Divorce

Divorce is no small matter ... even for reality TV stars Amy and Matt Roloff, who are pulling the plug on their 27 year marriage.

The "Little People, Big World" couple announced they were separating back in March, but filed divorce docs on Friday ... citing irreconcilable differences.

In a statement, the Roloffs said they were proud of raising their 4 kids to adulthood. It's interesting ... their youngest just turned 18 in January. Kinda looks like they waited to become empty nesters before ending things.