A veteran entering his 10th season, Dupree gives the Chargers another option along with Tuli Tuipulotu behind starters Khalil Mack and Joey Bosa.
Acquiring depth and boosting competition have been two of the consistent talking points of coach Jim Harbaugh and general manager Joe Hortiz since both joined the Chargers slightly more than three months ago.
Dupree, 31, had 6.5 sacks and 39 tackles in 16 games last season for Atlanta. A first-round pick (No. 22 overall) of Pittsburgh in 2015, he spent six years with the Steelers before going to Tennessee for two seasons.
A starter in 99 of his 119 NFL games, Dupree had his most productive year in 2019, when he finished with 11.5 sacks and forced four fumbles for Pittsburgh.
The Chargers have been hoping to pair Mack and Bosa as a forceful duo coming off the edge since trading for Mack in March 2022. But Bosa has been limited to nine starts over the past two seasons because of injury.