Miller was an All-Star in 2015, finishing with a 3.02 ERA and 171 strikeouts in 205.1 innings pitched.
Swanson, from Marietta, was the Diamonbacks’ No. 1 overall pick.
The deal also brought outfielder Ender Inciarte and pitching prospect Aaron Blair to Atlanta.
Stewart, who at one time represented Braves outfielder Matt Kemp, was fired in 2016 after two seasons (148-176) with Arizona.
The rookie shortstop is a preseason leading candidate for Rookie of the Year and excited about Braves' outlook. (Video by David O'Brien)