Black had been expected to be named the Washington Nationals' new manager earlier this month before talks hit a snag and the club hired Dusty Baker to manage the team instead.
The Padres fired Black in June, when his revamped team was underperforming with a 32-33 record despite the addition of several stars in the offseason.
In eight-plus seasons with the Padres, Black had a 649-713 record.
Black spent seven seasons as Angels manager Mike Scioscia's pitching coach, winning a World Series championship ring in 2002 before taking over the Padres in 2007.
The Angels hired Charles Nagy as their pitching coach earlier this month.
Eppler announced several additional front-office hires and promotions while welcoming back Black.
Former major league infielder Mike Gallego was named the club's director of baseball development. The UCLA product and Southern California native spent the past seven seasons as the Oakland Athletics' third base coach.
The Associated Press contributed to this report.