A wheat variety designated 26R20, the plants and seeds of wheat variety 26R20, methods for producing a wheat plant produced by crossing the variety 26R20 with another wheat plant, and hybrid wheat seeds and plants produced by crossing the variety 26R20 with another wheat line or plant, and the creation of variants by mutagenesis or transformation of variety 26R20. This invention also relates to methods for producing other wheat varieties or breeding lines derived from wheat variety 26R20 and to wheat varieties or breeding lines produced by those methods.