Mushroom mycelia of Antrodia camphorata, Agaricus blazei, Hericium erinaceus and Phellinus linteus were used to substitute 5% of wheat flour to make bread. Bread quality, including specific volume, colour property, equivalent umami concentration (EUC), texture profile analysis, sensory evaluation and functional components, was analysed. Mycelium-supplemented bread was smaller in loaf volume and coloured, and had lower lightness and white index values. White bread contained the lowest amounts of free umami amino acids and umami 5′-nucleotides and showed the lowest EUC value. Incorporating 5% mushroom mycelia into the bread formula did not adversely affect the texture profile of the bread. However, incorporating 5% mushroom mycelia into the bread formula did lower bread’s acceptability. After baking, mycelium-supplemented bread still contained substantial amounts of γ-aminobutyric acid and ergothioneine (0.23–0.86 and 0.79–2.10 mg/g dry matter, respectively). Overall, mushroom mycelium could be incorporated into bread to provide its beneficial health effects.