A source told the Chicago Sun Times' Sean Jensen that Lewis turned down a bigger offer from another team so he could return to the Big Easy.
"We are excited to be able to add a player of Keenan's ability to our defense," Saints general manager Mickey Loomis said in a statement released by the team. "He was a top free-agent target for us, and I know that he is very excited to be able to come home to play football."
Lewis failed to record an interception during his 2012 breakout season, but he did lead all NFL cornerbacks with 16 passes defensed while allowing just a 52.7 completion rate on throws in his territory.
Lewis is ideally suited to new coordinator Rob Ryan's defense, which has traditionally emphasized physical press-man cornerbacks. Lewis might not be the only addition, as Ryan reportedly has designs on signing Nnamdi Asomugha as well.
It's good to see the Saints taking a proactive approach to fixing their secondary after the team set the NFL single-season record for yards allowed last season.Follow Chris Wesseling on Twitter @ChrisWesseling.