A wheat variety designated W080400B2, the plants and seeds of wheat variety W080400B2, methods for producing a wheat plant produced by crossing the variety W080400B2 with another wheat plant, and hybrid wheat seeds and plants produced by crossing the variety W080400B2 with another wheat line or plant, and the creation of variants by backcrossing, mutagenesis or transformation of variety W080400B2 are disclosed. Methods for producing other wheat varieties or breeding lines derived from wheat variety W080400B2 and to wheat varieties or breeding lines produced by those methods are also provided.