The disclosure relates to a cotton variety, designated P04X.3074, the plants and seeds of the cotton variety P04X.3074, methods for producing a cotton plant, either varietal or hybrid, produced by crossing the cotton variety P04X.3074 with itself or with another cotton plant, hybrid cotton seeds and plants produced by crossing the variety P04X.3074 with another cotton variety or plant, methods for producing a cotton plant containing in its genetic material one or more transgenes, and the transgenic cotton plants produced by that method. This disclosure also relates to cotton varieties derived from cotton variety P04X.3074, to methods for producing other cotton varieties derived from cotton variety P04X.3074, and to the varieties derived by the use of those methods.