ESPN reported that the Bills and Marrone reached a deal early Sunday morning.
Marrone replaces Chan Gailey, who was fired last Monday after going 16-32 over three seasons, and inherits a club that hasn't reached the playoffs since 1999.
The 48-year-old Marrone compiled a 25-25 record in four seasons at Syracuse and his tenure with the Orange ended with a 38-14 victory over West Virginia in last month's Pinstripe Bowl.
Marrone has experience working in the NFL. He was an offensive line coach with the New York Jets and served as Sean Payton's offensive coordinator in New Orleans from 2006-08.
