In this study, sea buckthorn (Hippophae rhamnoides L.) pomace resulting from juice extraction was dried and ground in order to obtain a powder that was further used in bread making. Sea buckthorn pomace, an invaluable by-product of the industry, contains bioactive compounds and dietary fibers that promote health. Dried by-products of sea buckthorn are rich sources of nutritional and bioactive compounds, offering great potential for use as nutraceuticals in animal feed, ingredients in functional food, and the pharmaceutical industry. The utilization of sea buckthorn by-products promotes a circular and sustainable economy by implementing innovative methods and strategic approaches to recover high-value products and minimize waste in multiple ways. For this purpose, three organic sea buckthorn varieties were used, namely Mara (M), Clara (C), and Sorana (S). Further, 6%, 8%, and 10% pomace powder were added to wheat flour to prepare functional bread, and its effects on structural, nutritional, and sensorial characteristics were investigated. The volume, porosity, and elasticity of the obtained bread samples were slightly lower compared to the control sample (white bread). The nutritional characteristics revealed that the developed bread presented higher antioxidant activity, polyphenolic content, and crude fiber compared to the control sample. The acceptability test showed that consumer preferences were directed toward the bread samples containing 8% sea buckthorn powder, regardless of the variety, while the addition of 10% pomace powder led to major sensorial changes. The results of this study showed that sea buckthorn pomace powder can be successfully incorporated into bread in order to obtain a food product with enhanced properties.