The 2009 Siemens Open was a professional tennis tournament played on outdoor red clay courts.

This was the seventeenth edition of the tournament which is part of the Tretorn SERIE+ of the 2009 ATP Challenger Tour.

The following players received wildcards into the singles main draw: The following players received entry from the qualifying draw: Kristof Vliegen def.

Lucas Arnold Ker / Máximo González def.

Thomas Schoorel / Nick van der Meer, 7–5, 6–2