The USL team will provide a nearby outlet for Atlanta United to loan out little-used players to get additional experience, while also serving as a pathway to the professional ranks for United's academy players.
The new squad will play its matches at 10,427-capacity Coolray Field, home of the Atlanta Braves' Triple-A farm team.
United president Darren Eales says the Major League Soccer franchise now has the "capability to develop players in our system from the time they're 12 years old until the minute they reach the first team."
The club's name and crest will be released later.
The USL had 30 teams this season and will add at least four expansion franchises next season, with three more set to join in 2019.
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