He was named assistant head coach of the Bills on Monday, and will begin his 45th year in the NFL as a player and coach. The Bengals fired him in December after finishing with the NFL's worst record at 2-14.
LeBeau, 65, had been an assistant coach with the Bengals for 15 seasons before taking over after Bruce Coslet resigned following the third game of the 2000 season. He posted a 12-33 record during his tenure, the worst winning percentage of any of the eight head coaches in franchise history.
LeBeau played cornerback with the Detroit Lions from 1959-72, and was voted to three Pro Bowls. He also was an assistant with the Philadelphia Eagles, Green Bay Packers, and Pittsburgh Steelers.
In Buffalo, he will be reunited with linebackers Takeo Spikes, who also will join the Bills next season after Cincinnati declined to match Buffalo's offer sheet.