The agreement was first reported by MLB Network's Jon Heyman. The Padres have not announced the deal.
Rodney, who turns 39 in March, began the 2014 season as the Mariners' closer but was designated for assignment in August and later traded to the Cubs.
Rodney, who has 236 saves in 13 big league seasons with the Tigers, Rays, Angels, Mariners and Cubs, led the Majors in saves with 48 for Seattle in 2014. He had a 5.68 ERA and 16 saves in 54 appearances with the Mariners last season, blowing six save opportunities.
Rodney had better luck with the Cubs, albeit in a short stay, allowing one run and striking out 15 in 12 regular-season innings. He allowed two runs in 1 2/3 innings in two postseason games, yielding a home run to Daniel Murphy of the Mets in Game 4 of the National League Championship Series.
The Padres, who currently have a payroll of about $101 million, were looking for some help and experience for the later innings of games after trading Kimbrel to the Red Sox and Joaquin Benoit to the Mariners earlier in the offseason.
The team also recently opted to move right-hander Brandon Maurer, one of its top relievers last season, into the starting rotation.
Fantasy spin | Fred Zinkie (@FredZinkieMLB)
Rodney managed to survive a 1.34 WHIP across the 2013-14 seasons, logging a 3.11 ERA and converting 85 of 96 save chances. His good fortune ran out when he posted a 5.68 ERA and a 1.50 WHIP on route to losing his closer's role with the Mariners last year, but he got back on track during a 12-inning trial with the Cubs, recording a 0.75 ERA and 1.00 WHIP. The ninth-inning gig is readily available with San Diego, and Rodney should join Kevin Quackenbush and Jon Edwards in a wide-open competition this spring. While he is unlikely to deliver helpful ratios, the 38-year-old will warrant a roster spot in deep-mixed formats if he can secure the closer's job. Having compiled 133 saves from 2012-14, Rodney has proven that he can handle the pressure of the final frame.
Corey Brock is a reporter for MLB.com. Keep track of @FollowThePadres on Twitter and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.