The 2009 Mercedes Cup was a man's tennis tournament played on outdoor clay courts.

It was the 32nd edition of the Stuttgart Open and was part of the ATP World Tour 250 series of the 2009 ATP World Tour.

It was held at the Tennis Club Weissenhof in Stuttgart, Germany, from 11 July 11 until 19 July 2009.

Jérémy Chardy won the singles title.

The following players received wildcards into the singles main draw The following players received entry from the qualifying draw: Jérémy Chardy defeated Victor Hănescu, 1–6, 6–3, 6–4 František Čermák / Michal Mertiňák defeated Victor Hănescu / Horia Tecău, 7–5, 6–4