In Week 14, he collected a season-high eight solo tackles during a 20–16 win at the Detroit Lions. Sharper started in all 16 games for the third consecutive season and recorded 69 combined tackles (60 solo), five pass deflections, and an interception. He finished his four-year career in Minnesota with 18 interceptions, 250 tackles, 359 interception yards, three touchdowns, and a sack. On March 18, 2009, the New Orleans Saints signed Sharper to a one-year, $1.20 million contract. Throughout training camp, Sharper competed to be the starting free safety against Usama Young. Head coach Sean Payton named Sharper the starting free safety to begin regular season, alongside strong safety Roman Harper and cornerbacks Jabari Greer and Tracy Porter. He started in the New Orleans Saints' season-opener against the Detroit Lions and recorded one tackle, deflected two passes, and made two interceptions off pass attempts by quarterback Matthew Stafford during a 45–27 victory. The following week, Sharper recorded three solo tackles, broke up a pass, and returned an interception by quarterback Kevin Kolb for a 97-yard touchdown during the fourth quarter of a 48–22 win at the Philadelphia Eagles in Week 2. On October 4, 2009, Sharper made nine combined tackles, two pass deflections, two interceptions, and a touchdown during a 24–10 win against the New York Jets in Week 4. Sharper intercepted a pass by Jets' quarterback Mark Sanchez and returned it for a 99-yard touchdown in the second quarter. The return for touchdown became his second 95+ yard interception return of the season. In Week 7, Sharper made four combined tackles, broke up a pass, and returned an interception by Chad Henne for a 42-yard touchdown during a 46–34 win at the Miami Dolphins. Sharper was inactive for the Saints' Week 10 victory at the St. Louis Rams after straining his left knee. On December 27, 2009, Sharper made seven combined tackles, two pass deflections, and returned an interception by Josh Freeman for a 21-yard gain during a 20–17 loss to the Tampa Bay Buccaneers in Week 16. The 21-yard interception brought his season return yards to 376-yards and earned him the record for most interception return yards in a single season. He surpassed Ed Reed who set the record in 2004. It was the 63rd interception of Sharper's NFL career, tying him for sixth on the all-time list. On December 29, 2009, it was announced that Sharper was selected to play in the 2010 Pro Bowl.