|Open Sud de France|
|Venue||Palais des Sports de Gerland (1987-2009)|
Arena Montpellier (2010-current)
|Category||ATP World Series|
ATP International Series
ATP Tour 250
|Surface||Hard - indoors|
|Draw||28S / 16Q / 16D|
|Prize money||€501,345 (2018)|
|Current champions (2021)|
|Men's singles||David Goffin|
|Men's doubles|| Henri Kontinen |
The Open Sud de France (formerly known as the Grand Prix de Tennis de Lyon) is a professional tennis tournament played on indoor hard courts. It is currently part of the ATP Tour 250 series of the ATP Tour. It was held annually at the Palais des Sports de Gerland in Lyon, France, in October, from 1987 through to 2009, before being relocated to Montpellier in 2010. The tournament takes place at the Montpellier Arena, holding 7,500 spectators.
The tournament is one of four French events of the ATP Tour 250 series, along with the Open 13, the Moselle Open, and the Lyon Open. There was no event in 2011 as the tournament moved to a January slot in 2012.