Two of the greatest boxers of all-time have agreed to a fight ... TMZ Sports has learned Mike Tyson and Floyd Mayweather have signed a deal to square off against one another!!
We're told the match -- which will be put on by CSI Sports/Fight Sports -- is currently scheduled for sometime in the spring of 2026.
An exact date and precise location are not yet known ... but nonetheless, Tyson said he's thrilled to be slated to mix it up with Floyd, whom he hasn't always had the greatest relationship.