Per Marc J. Spears of The Undefeated, the Hawks will officially introduce Pierce at a press conference Monday.
ESPN's Adrian Wojnarowski added Pierce's deal will be for three years with the Hawks holding an option for a fourth year.
Pierce has served as an assistant coach for the Philadelphia 76ers since 2013. He previously worked in player development with the Cleveland Cavaliers and Memphis Grizzlies and spent four months with the Golden State Warriors during the 2010-11 season.
The Hawks parted ways with Mike Budenholzer on April 25 after going 24-58 during the 2017-18 season. It was the franchise's worst single-season record since the 2004-05 campaign and first time they missed the playoffs since 2006-07.
Pierce's background in player development will mesh well with Atlanta's current roster. Dennis Schroder and Taurean Waller-Prince are both 24 years old, and the Hawks have the fourth-best odds to win the No. 1 overall pick in the 2018 NBA draft lottery May 15.