A novel soybean cultivar, designated 90362421, is disclosed. The invention relates to the seeds of soybean cultivar 90362421, to the plants of soybean 90362421 and to methods for producing a soybean plant produced by crossing the cultivar 90362421 with itself or another soybean variety. The invention further relates to hybrid soybean seeds and plants produced by crossing the cultivar 90362421 with another soybean cultivar.