The aim of the work was to determine the influence of brown algae on the physical, antioxidant, and sensorial properties when added directly into the gluten-free bread (GFB) recipe. Algae powder was added in the amounts of 2%, 4%, 6%, 8%, and 10% of the total flour content. Compared to the control bread, a larger volume was obtained using 4% of algae. With an increased content of brown algae, significant changes were noted in the color of the breadcrumb. Favorable changes in the texture were also observed. Brown algae addition significantly increased the antioxidant activity of GFB. Most importantly, antiradical compounds from the functional products were highly bioaccessible in vitro. The results confirm the possibility of the use of brown algae powder in the production of GFB. Because of the unpleasant taste on over-addition, the acceptable GFB can be obtained by adding 2% or 4% of the algae.