The actor - who has appeared on ABC soap General Hospital since 1993 - will play bad boy musician Avery, according to Deadline.
Nashville will focus on the eponymous city's music scene, with Jackson's character described as an "aspiring songwriter".
Jackson previously played Kyle Reese on Fox drama Terminator: The Sarah Connor Chronicles and also appeared in 2002 Al Pacino film Insomnia.
The Nashville pilot has been written by Thelma & Louise scribe Callie Khouri and will be directed by RJ Cutler.
Other drama pilots under consideration at ABC include Marc Cherry's Devious Maids, Last Resort from The Shield creator Shawn Ryan and a remake of Dutch series Penoza.
> Chris Egan joins ABC pilot Beauty and the Beast