Redding was drafted in the third round (66th overall) of the 2003 NFL Draft by the Detroit Lions. In his rookie season he played in nine games and made seven tackles. The following season, 2004, he became the teams starting left defensive end and started in all sixteen of the Lions games and made 40 total tackles and three sacks. In a game vs the Minnesota Vikings he tackled Vikings running back Onterrio Smith for a safety.
In 2005, he once started all sixteen games for the Lions and made 31 total tackles, one sack and batted down four passes attempts. In 2006, he had a breakout season as he made a professional career high 47 total tackles, eight sacks and two forced fumbles.
In 2007, Redding became a free agent but the Lions made him their franchise player (making them the only team that he can work out a contract with). On July 16, he signed with the Lions to the largest contact (seven-year, $49 million) ever for a NFL defensive tackle.