The Steelers running backs coach for the last four years has decided to move on, a source told ESPN.
The Steelers said in a statement that Williams has agreed to a four-year contract with the team that begins in the 2016 season.
The move leaves Williams as the longest-tenured coach in the league.
Williams was a third-round draft pick in 2009, and he was the Bengals offensive coordinator from 2011 to 2013 before becoming the Bengals running backs coordinator in 2014.
Williams coached the Bengals to a Super Bowl title in 2015, and the Bengals made the playoffs in 2017.
Williams spent the last two seasons as an offensive assistant to the Bengals’ offensive coordinator, Andy Dalton.
The Bengals announced on Tuesday that they have fired coach Marvin Lewis.