According to the invention, there is provided a novel soybean variety designated XB07S09. This invention thus relates to the seeds of soybean variety XB07S09, to the plants of soybean XB07S09 to plant parts of soybean variety XB07S09 and to methods for producing a soybean plant produced by crossing plants of the soybean variety XB07S09 with another soybean plant, using XB07S09 as either the male or the female parent.