District 9 (German: Stadtbezirk 9) is a southern city district of Düsseldorf, the state capital of North Rhine-Westphalia, Germany. The district covers an area of 36,59 square kilometres and (as of December 2009) has approximately 89,000 inhabitants, making it the city's second most populous district after District 3. The district borders Düsseldorf Districts 3 and to the north, and to the south. To the east and west the district borders the rural districts of Kreis Mettmann and Rhein-Kreis Neuss respectively.