The former couple did not go public with their split until 2009 when Mel was photographed embracing a new girlfriend.
TMZ said Robyn's attorney, Laura Wasser, appeared in court Tuesday morning and said the Gibsons were in full agreement on the terms of their divorce.
The final paperwork is being drawn up and the divorce is expected to be finalized by the end of August, the celebrity news Web site said.
The parents of seven children separated shortly after Gibson's infamous drunken driving arrest, during which he made outrageous remarks perceived by many to be anti-Semitic. He later apologized for his behavior.