ReutersFinancial terms of the deal, which will keep Johnson under contract through the 2019 NFL season, were not disclosed but a report on the team's website said it was worth $132 million.
The team is holding a news conference at 1700 GMT.
Johnson is coming off one of the best seasons ever for a wide receiver as he became just the third player to record at least 95 catches, 1,600 yards and 15 touchdowns.
His 96 catches for 1,681 yards and 16 touchdowns during the 2011 campaign were all career highs and helped the Lions return to the playoffs for the first time since the 1999 season.
Johnson, taken by Detroit with the second pick in the 2007 NFL Draft, is a two-time Pro Bowler with 5,872 yards and 49 touchdowns in five seasons.
