The 2005 Grand Prix de Tennis de Lyon was a men's tennis tournament played on indoor hard courts. It was played at the Palais des Sports de Gerland in Lyon in France and was part of the 2005 ATP Tour. It was the 19th edition of the tournament and took place from October 24 through October 31, 2005.
Andy Roddick defeated Gaël Monfils 6–3, 6–2
- It was Roddick's 5th title of the year and the 22nd of his career.
Michaël Llodra / Fabrice Santoro defeated Jeff Coetzee / Rogier Wassen 6–3, 6–1
- It was Llodra's 3rd title of the year and the 9th of his career. It was Santoro's 3rd title of the year and the 21st of his career.