The couple married in December 1993 and have five children, including 20-year-old singer-actress Miley Cyrus.
People.com said Billy Ray previously filed divorce papers three years ago, then withdrew them saying he wanted to keep his family together; however, Tish moved to officially end their marriage Thursday.
"This is a personal matter and we are working to find a resolution that is in the best interest of our family. We ask that you respect our privacy at this time," she told People.com in a statement.
Notable deaths of 2014 [PHOTOS]