Heisey will make $1,325,000 and Simon will earn $890,000. The deals were announced by the Reds on Thursday.
The 28-year-old Heisey batted .265 with seven homers and 31 RBIs in 120 games for the Reds last season. It was a considerable dropoff for Heisey: In 2011, his second year in the majors, he also appeared in 120 games but hit 18 homers in 68 fewer at-bats.
Simon, 31, went 3-2 with a 2.66 ERA in 36 relief appearances in his first year with the Reds after parts of four seasons in Baltimore.