The 31-year-old forward confirmed his return on his Twitter account.
"I'm excited to be back in the A next season! #TrueToAtlanta," Humphries wrote.
Humphries, a journeyman who has played for eight teams during his 12-year career, has averaged 6.8 points and 5.5 rebounds in 744 games.
Humphries signed with the Hawks on Mar. 1 for the rest of the season, averaging 6.4 points and 3.4 boards over 21 games.
In 53 total games last year, Humphries averaged 6.5 points and 4.1 rebounds.
Humphries was the No. 14 overall pick of the Utah Jazz in the 2004 draft.