The free-agent forward is finalizing a three-year, $61.5 million contract with the Atlanta Hawks, his agent, Michael Tellem of CAA Sports, told ESPN's Adrian Wojnarowski.
Over the past week, the retooling Thunder have made multiple moves, including sending Chris Paul to the Phoenix Suns, Dennis Schroder to the Los Angeles Lakers, Kelly Oubre Jr. to the Golden State Warriors and Ricky Rubio to the Minnesota Timberwolves, and a trade in which they acquired Al Horford from the Philadelphia 76ers.
Gallinari, 32, is one of the prize free agents of this class because of his unique combination of size and shooting. With the Thunder last season, Gallinari was a vital part of the team's surprising run to the fifth seed in the Western Conference.
With the Thunder managing his minutes and workload, Gallinari, 32, had one of the healthiest seasons of his career in 2019-20. He missed only 10 games, the fewest since he played in 81 during his second season in the NBA.
The 6-10 forward averaged 18.7 points and 5.2 rebounds while making 40.5% from 3-point range last season with OKC.
Gallinari is a free-agent oddity, a player over the age of 30 who signed for $20 million-plus per year and has never made an All-Star team, a first under the most recent collective bargaining agreement (2017).
With the flurry of moves prior to the draft as the Thunder shift their direction toward a youth-focused rebuild, Gallinari wasn't likely to return. He nearly was dealt at the trade deadline last season, but after a deal with Miami never came together, he stayed with OKC for the remainder of the season.
The Hawks are Gallinari's fifth team in 12 seasons. He has played for the New York Knicks, Denver Nuggets, LA Clippers and Thunder and has been traded three times, most recently as part of the blockbuster deal that sent Paul George to the Clippers in July 2019. Gallinari helped the Thunder exceed expectations by finishing fifth in the Western Conference before they took the Houston Rockets to seven games in a tight first-round series.