NFL Network's Jason La Canfora, citing a league source, reported that Hartley also will remain with the club. La Canfora said another player will be cut to make room on the roster for Carney.
This season he made a partially blocked 37-yard, game-winning field goal at the end of regulation of New Orleans' Week 2 triumph at San Francisco.
Carney, the third-leading scorer in NFL history, was the Saints' kicking consultant when they won the title, a job the 22-year NFL veteran moved into after spending most of the 2009 regular season on the active roster.
The Saints brought in Carney last season after Hartley was suspended four games after testing positive for the banned stimulant Adderall. Carney remained an active player for 11 games, making 13 of 17 field goals, with a long of 46 yards.
He also was with the team from 2001 to '06, making 150 of 180 field-goal attempts (5 of 9 from 50-plus yards).
Carney kicked in college for Notre Dame from 1984 to '86 and failed to make the Cincinnati Bengals' regular-season roster in 1987, finally appearing in a game the following season.
Carney has made 473 field goals in his career. He still has a ways to go to match Morten Andersen, who kicked until he was 47, making 565 field goals during 25 seasons. Andersen's last season was 2007.
The Associated Press contributed to this report.