Floyd, who has played for Minnesota, New England and Arizona, made 10 catches for 78 yards in 11 games with the Vikings last season. He appeared in two games with the Patriots in 2016 after he was released by the Cardinals after being charged with an extreme DUI.
Floyd, 28, was suspended for four games under the NFL's substance abuse policy and spent a day in jail after his conviction in 2017.
He caught 242 passes for 3,739 yards and 23 touchdowns in 76 games with Arizona in five seasons.
Floyd, the 13th overall pick in the 2012 NFL Draft out of Notre Dame, is expected to compete for the No. 3 wide receiver spot behind Michael Thomas and Ted Ginn.
New Orleans also signed wide receiver Brandon Tate. He recorded 71 catches for 1,099 yards and seven touchdowns in seven seasons with New England (one), Cincinnati (four) and Buffalo (two).