Caldwell spent the last 10 seasons with the Colts, including the last two as western regional scout.
Caldwell will assume the same position with Atlanta that Dimitroff held in New England before he was hired by the Falcons this year.
"He comes to us from a highly respected and very successful team," said Dimitroff of Caldwell. "He is well respected around the NFL and will be a great asset to the scouting department."
Copyright 2008 by The Associated Press