A soybean cultivar, designated 1000109, is disclosed. The invention relates to the seeds of soybean cultivar 1000109, to the plants of soybean 1000109 and to methods for producing a soybean plant produced by crossing the cultivar 1000109 with itself or another soybean variety. The invention further relates to hybrid soybean seeds and plants produced by crossing the cultivar 1000109 with another soybean cultivar.