Bell's hiring was announced Monday. He had been with Florida State for the 2018 season and is now set to be a head coach for the first time in his career.
In a statement released by the school, the 34-year-old Bell described himself as being "immensely excited" to take over in Amherst.
UMass announced nearly two weeks ago that Mark Whipple was stepping down as head coach and that it was a mutually agreed upon separation. Whipple had coached five seasons at the University of Massachusetts, and was previously the head coach at the school from 1998-2003 as well, amassing a total of 65 wins at the university.
"I want to thank Mark for his commitment to our football program for 11 years. He came back to UMass when this program needed a strong leader and respected mentor," said UMass athletic director Ryan Bamford. "Mark provided the steady hand we needed in our early years as an FBS program and leaves our program in much better standing than when he came back in 2014. His legacy is not only cemented in his 65 wins and our 1998 FCS national championship, but in the way he positively impacted hundreds of young men in his program."
The program has gone 4-8 in each of the past two seasons, though an improvement over a 2-10 2016 campaign.
The son of a coach, Bell was the offensive coordinator and quarterbacks coach at Florida State for the 2018 season. He held the same position at Maryland for two seasons prior to that. Bell's stops before that included assistant head coach and offensive coordinator at Arkansas State and tight ends coach at North Carolina.
A football independent, UMass became a full FBS member in 2013 after a two-year transition period from FCS.