Postmenopausal osteoporosis is characterized by progressive bone loss and an increased risk of fractures, while current pharmacological approaches mainly suppress bone resorption and present long-term limitations. This study aimed to evaluate the anti-osteoporotic potential of enzymatic hydrolysates derived from salmon (Oncorhynchus keta) head by-products (SBPE) as asustainable nutraceutical candidate for bone health. The hydrolysates from salmon (Oncorhynchus keta) head by-products were generated via peptic digestion, and chondroitin sulfate content was quantified using LC– MS/MS and revealing an average level of 124.33 ± 10.07 μg/mg. Osteogenic activity was evaluated in osteoblast cultures, zebrafish, and ovariectomized (OVX) rats. In MC3T3-E1 osteoblasts, SBPE increased alkaline phosphatase (ALP) activity by 16 ± 2.18%, elevated osteoprotegerin (OPG) expression by 8.76 ± 1.24%, and reduced receptor activator of nuclear factor-κB ligand (RANKL) levels by 11.71 ± 1.77%, indicating enhanced osteogenic differentiation. SBPE also significantly increased skeletal mineralization in zebrafish in adose-dependent manner (25–100 μg/mL) and preserved bone mass and trabecular architecture in OVX rats. X-ray micro-computed tomography (Micro-CT) analysis confirmed structural improvement, while serum osteocalcin and alkaline phosphatase levels increased without adverse effects. These findings demonstrate that chondroitin sulfate-enriched salmon by-product hydrolysates exert bone-protective effects across multiple models, highlighting their potential as asustainable nutraceutical resource for preventing postmenopausal osteoporosis and promoting bone health.