According to the invention, there is provided a novel soybean variety, designated XB19U04. This invention thus relates to the seeds of soybean variety XB19U04, to the plants of soybean XB19U04, and to methods for producing a soybean plant by crossing soybean variety XB19U04 with another soybean plant, using XB19U04 as either the male or the female parent. This invention also relates to methods for introducing a transgene into soybean variety XB19U04 and plants produced by those methods.