<p>The main aim of the present study is to fabricate a 3D scaffold loaded with bioglass nanofibers to orchestrate robust bone regeneration via enhanced osteogenesis and mineralization. We applied a sol–gel method to fabricate the bioglass nanofibers and incorporated them into 3-D hydrogel (1%, 5%, and 10% wt.%). The fabricated scaffolds were characterized to determine their morphology, surface functional groups, porosity, swelling capacity, biodegradation profile, cytocompatibility, and hemocompatibility. Finally, the scaffolds were implanted in critical-size bone-defect models in the rabbit calvaria. The results showed that the calcination of precursor nanofibers to fabricate bioglass nanofibers reduced the nanofibers' diameter from around 981 nm to around 566 nm. Hydrogels containing 0%, 1%, and 5% BGNFs demonstrated no cytotoxicity, with viability percentages of 113%, 105.7%, and 112%, respectively. The 10% BGNF formulation exhibited a minor decrease in vitality (84.3%). Notably, the scaffolds promoted osteogenesis to a high degree, as evidenced by a concentration-dependent increase in mineral deposition under Alizarin Red staining. The animal studies showed that scaffold implantation supported new bone formation, as evidenced by histological analysis and micro-CT imaging. A denser, more interconnected bony network with superior mineralization (BMD) was the result of a remarkable rise in bone volume (BV/TV), trabecular thickness (Tb.Th), and trabecular number (Tb.N), as well as a decrease in trabecular separation (Tb.Sp). The most significant outcomes were achieved when stem cells were combined with the BGNF scaffold. In summary, these results demonstrate that the bioactive nanocomposite scaffold is an excellent starting point for functional bone repair.</p>