New acts confirmed for Southbound include Blake Shelton, Charlie Worsham, Jerrod Niemann as well as Vince Gill, Hunter Hayes and Dann Huff on guitar. Previously announced guests include Brad Paisley, Sara Evans, Zac Brown Band, Chris Young, Toby Keith, Love and Theft and Amanda Sudano of JohnnySwim.

In an interview with Lagniappe Mobile, Doobie Brothers' Tom Johnston talked about the album's guests. "It's quite the lineup," he said. "We were kinda blown away that these folks would be interested in jumping on board with us, but they were eager to do it."