The former couple had apparently had a trial separation and have decided to move forward.
He made the announcement on Twitter.
MacKenzie was one of Bezos' first Amazon employees.
Jeff Bezos is now worth over $141 billion, making him the richest man in the world.
There's no word if the couple had a pre-nuptial agreement. If not, the divorce could be one of the most expensive ever.
The Bezos' have four children and have been together for 25 years.