According to legal records obtained by CNN, she filed last week in Williamson County, Tenn.
The documents say the grounds for divorce are “irreconcilable differences.”
The filing also states the couple has not lived together in the last two years.
Tish, 54, and Billy Ray Cyrus, 60, married in 1993 and have five adult children: Trace, Braison, Brandi, Miley and Noah.
A representative for the Cyrus’s told People in a joint statement, “It is after 30 years, five amazing children and a lifetime of memories, we have decided to go our separate ways — not with sadness, but with love in our hearts.”
“We will always be family and look forward to a continued and loving shared experience as friends and parents,” the statement continues.
“We have not come to this decision lightly or quickly but with so much going on in the world, we wanted to provide some clarity and closure, so we can remain focused on what is important.”
This is the third time the couple has filed for divorce.
In 2010, the Achy Breaky Heart singer filed to divorce Tish Cyrus, but called it off six weeks later.
Then again in 2013, Tish filed to divorce her husband, though they reconciled once more.
The couple said marriage counselling brought them back together.
As of this writing, none of the couple’s five children have commented publicly on the split.