Sea buckthorn (Hippophae rhamnoides L.) is a rich source of bioactive compounds, including vitamin C, polyphenols, carotenoids, and dietary fiber. In this study, sea buckthorn pomace, an underutilized by-product of oil processing, was incorporated into wheat bread at levels of 0, 3, 6, 9, and 12% (based on flour weight). The technological performance (dough yield, baking loss, loaf volume, texture, and color), nutritional composition (protein, fat, dietary fiber fractions, mineral content, and caloric value), and sensory attributes of the resulting breads were comprehensively evaluated. Pomace addition markedly increased the protein content of bread (from 13.5% to 16.8%) and more than doubled total dietary fiber (from 5.4% to 11.6%), while reducing caloric value by approximately 5.6%. Increasing pomace levels also affected dough behavior and bread structure: water absorption rose from 59.9% to 68.9%, specific loaf volume decreased by 11–28%, and crumb hardness increased from 3.8 N (control) to 12.4 N (12% addition). Sensory acceptability remained high up to 6% pomace incorporation (acceptability index > 90%), whereas breads containing 9–12% received significantly lower scores, mainly due to darker crumb color and intensified sour or bitter notes. Overall, sea buckthorn pomace can be effectively used as a nutritionally enriching, value-added ingredient in wheat bread, enhancing fiber and protein content while maintaining desirable technological and sensory properties at moderate substitution levels.