The pair collectively boast 445 appearances in Major League Soccer, adding valuable experience to head coach Gary Smith's inaugural MLS roster.
McCarty, 32, is a two-time Supporters' Shield winner and has played for the United States men's national team on 13 occasions. The veteran midfielder was acquired from the Chicago Fire in exchange for $50,000 in general allocation money (GAM), $50,000 in targeted allocation money, and a second-round pick in the 2021 MLS SuperDraft.
Romney, meanwhile, moves to Tennessee after representing the LA Galaxy for five seasons. The 26-year-old defender cost Nashville $225,000 in GAM, with a further $50,000 in GAM owed to the Galaxy if Romney meets performance-based metrics.
There are currently seven other players signed to Nashville's squad for the 2020 MLS campaign: