Mel Gibson — Single by Sundown

Mel Gibson will officially be back on the market by the end of the day … because a judge is about to sign his divorce decree.

The couple and their lawyers have been negotiating a financial settlement for more than a year, and we’re told the deal has finally been struck.

Now, the paperwork has been submitted, the judge will sign off and Mel will be a single guy by the end of the day.

There was no prenup — remember, they were married for 28 years before officially separating.  Although there are reports the Gibsons’ net worth approached $900 million, but we’re told it’s less.

The couple separated back in 2006 — shortly after his infamous Malibu DUI arrest — and Robyn filed for divorce in 2009 — shortly after learning Mel’s then GF Oksana Grigorieva was pregnant.

The divorce has been surprisingly civilized, with Robyn even writing a letter of support for Mel last year … in his legal war with Oksana Grigorieva.  Robyn wrote in all the years she was with Mel, he never struck anyone in their family.