A baseball source confirmed to MLB.com that Dobbs agreed to a two-year deal worth $3 million, pending completion of his physical.
The free agent had attracted interest from several teams, including the Nationals. He was a bargain last season, signing a Minor League deal with an invitation to Spring Training.
The 33-year-old was initially used as a left-handed bat off the bench, but he ended up getting regular playing time, mainly at third base. The veteran was one of the Marlins' most productive players last year, batting .275 with eight home runs and 49 RBIs in 411 at-bats.
Dobbs made a big impact as a pinch-hitter, hitting .370 (10-for-27) with a home run and eight RBIs.
The Marlins are reshuffling their infield with the addition of Jose Reyes at shortstop and Hanley Ramirez moving to third base. Dobbs provides depth at both corner-infield positions.
Dobbs broke in with Seattle in 2004 and played in Philadelphia from 2007-10. He is a career .264 hitter with 39 homers and 211 RBIs in 689 games.