Kupp has not played since he sustained a knee injury on Oct. 14 in a game against the Denver Broncos.
"You're talking about a great football player that [is] extremely trustworthy in crunch-time situations or really throughout the course of the game," Rams head coach Sean McVay told reporters on Friday when he announced that Kupp will return. "His knowledge, his understanding of what we're trying to get done, his ability to compete with and without the ball. He's a special player.
"So getting somebody like him back that's had as much production as he has really since he got here last year is going to be big for our offense."
Having Kupp available will help the Rams exploit any openings in the Saints' defense as they try to put the clamps on running back Todd Gurley and the Rams' ground game.
The 6-foot-2, 208-pound Kupp, who was selected in the third round (69th overall) of the 2017 NFL Draft out of Eastern Washington, has 30 receptions for 348 yards and five touchdowns this season. As a rookie, he caught 62 balls for 869 yards and two scores.