The Open Sud de France (formally 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 World 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 will take place in the ARENA, holding 7,500 spectators.
The tournament is one of the three French events of the ATP World Tour 250 series, with the Open 13and the Open de Moselle.
There was no event in 2011 as the tournament moved to a January slot in 2012