Savage Garden Singer Darren Hayes Files to Divorce Husband Richard Cullen

Savage Garden lead singer Darren Hayes is ready to turn the page on his marriage -- after splitting up with his hubby, Richard Cullen, earlier this year ... he has now officially filed for divorce.

Hayes filed his dissolution docs Monday in Los Angeles, citing irreconcilable differences.

Darren and Richard have been together for a long time. They first got hitched way back in 2005, entered a civil partnership the year after ... and then got married again (here in the States) in 2013 to celebrate gay rights.

They have no children together, but presumably share a lot of other assets ... which will get divvied up as the divorce moves along.

Darren announced he and Richard were separating back in May, writing .... "After 17 years of marriage to the best person I have ever met, Richard and I have chosen to accept that our union has gently and beautifully come to rest. In honour of this realization, we separated earlier this year and have been supporting each other emotionally throughout this massive change in our lives."

He also addressed any speculation as to why they're going their separate ways, saying ... "Because people will ask, let me answer the ugly questions to get them out of the way forever - no, there's no scandal to report, no infidelity, guilty or third party."