Mel Gibson's dad has just filed for divorce ... TMZ has learned.
93-year-old Hutton Gibson cited irreconcilable differences from Teddy Joye Gibson, who is in her 70's.
Hutton -- interestingly -- is asking for spousal support. He also wants her to pay attorney's fees.
Hutton had no kids with Teddy, but had 11 kids with his first wife, Anne, and more than 50 grandchildren.
Also interesting ... Hutton is a devout Catholic and his religion does not believe in divorce.
The couple married in 2002.