McAdoo was fired from the New York Giants along with general manager Jerry Reese on Dec. 4 after posting a 2-10 mark this season and 13-15 record overall. The move came less than a week after the benching of two-time Super Bowl MVP quarterback Eli Manning created a backlash from fans.
The Giants struggled mightily on offense under McAdoo's watch this season, scoring just 17.8 points per game and ranking 30th in total yards per contest (314.7).
The Browns were the only team to finish with a worse record than the Giants, going 0-16 to secure the No. 1 overall pick in the 2018 NFL draft.
McAdoo spent two years as the Giants' offensive coordinator before being promoted to head coach. Prior to that, the 40-year-old McAdoo served as the Packers' tight ends and quarterbacks coach and had ties in Green Bay with new Browns general manager John Dorsey.
Coach Hue Jackson, who has called the offense's plays the past two seasons in Cleveland, already has one member of McAdoo's former Giants staff as an assistant. He hired Adam Henry to coach wide receivers last week.