Unione Sportiva Castelnuovo Garfagnana are an Italian association football club, based in Castelnuovo di Garfagnana, Tuscany.

In 1999–2000, Castelnuovo gained a surprising third place, and qualified for the promotional playoffs, losing 2–1 (on aggregate) in the semifinal round to Prato.

In 2002–2003, with a fourth place in the final table, Castelnuovo again qualified for the promotion playoffs, but again lost in the semifinal round; 5–2 on aggregate to Gubbio.

The 2007–08 season saw Castelnuovo finish in 15th place, forcing it to play in the relegation playouts against Rovigo, where it won after a 3–3 aggregate score (higher classified teams are considered the winners on aggregate ties).

Although it escaped relegation to Serie D, the club was liquidated on 30 June 2008 due to financial troubles,[1] and restarted from the Eccellenza league.