The deal will run through the 2020-21 season, Athletics Director Jim Miller said.
"Chris Mooney has demonstrated that he is the right fit for the University of Richmond. He has attracted quality student-athletes and guided them to success both on the court and in the classroom," Miller said.
The big contact comes after Mooney took Richmond to a 29-8 season, during with the Spiders won their first-ever Atlantic 10 Conference title and reached the Sweet 16 of the NCAA Tournament before bowing to Kansas.
Mooney, the team's head coach since 2005-06, has compiled a 112-87 record.