Patsos has spent the last nine seasons with the Greyhounds, leading them to an NCAA tournament appearance last season and advancing to the CollegeInsider.com tournament (CIT) this season. Prior to that, he was an assistant under Gary Williams at Maryland for 13 seasons.
Siena fired Mitch Buonaguro last month after the Saints went just 8-24 this season. He had won just 35 games in three seasons, never finishing above sixth place in the league.
With Loyola (Md.) leaving for the Patriot League next season, Patsos will now get a chance to stay in the MAAC.
Robert Morris head coach Andy Toole and VCU associate head coach Mike Rhoades were also in the mix for Siena.