2009 International German Open

The 2009 International German Open was a men's tennis tournament played on outdoor red clay courts. It was the 103rd edition of the event known that year as the International German Open and was part of the ATP World Tour 500 series of the 2009 ATP World Tour. It took place at the Am Rothenbaum in Hamburg, Germany, from 20 July through 26 July 2009.

Seeds
*Seedings based on 13 July 2009 rankings.

Other entrants
The following players received wildcards into the singles main draw
 * 🇩🇪 Daniel Brands
 * 🇩🇪 Florian Mayer
 * 🇩🇪 Simon Greul
 * 🇩🇪 Kevin Krawietz

The following players received entry from the qualifying draw:
 * 🇮🇹 Potito Starace
 * 🇷🇴 Victor Crivoi
 * Pablo Cuevas
 * 🇷🇺 Evgeny Korolev
 * 🇪🇸 Pere Riba
 * 🇪🇸 Marcel Granollers-Pujol

Singles
🇷🇺 Nikolay Davydenko defeated 🇫🇷 Paul-Henri Mathieu, 6–4, 6–2
 * It was Davydenko's first title of the year, and his 15th overall.

Doubles
🇸🇪 Simon Aspelin / 🇦🇺 Paul Hanley defeated 🇧🇷 Marcelo Melo / 🇸🇰 Filip Polášek, 6–3, 6–3