Background <p>Green synthesis of silver nanoparticles (Ag–NPs) using biological resources offers a sustainable alternative to conventional chemical methods. While plants and microbes are commonly employed, insect-derived biomaterials remain largely unexplored. This study investigates <i>Musca domestica</i> L. (houseflies) extract as a novel bioresource for rapid, chemical-free biosynthesis of Ag–NPs, transforming an underutilized organism into a value-added scientific resource.</p> Methods and results <p>Ag-NP formation was initially indicated by a visible color change and confirmed via UV–Vis spectroscopy, revealing a surface plasmon resonance peak at 475 nm. SEM analysis showed predominantly spherical nanoparticles with an average size of 76 ± 6 nm, while XRD confirmed a face-centered cubic crystalline structure with a crystallite size of 9.72 nm. FTIR analysis identified functional groups associated with proteins, phenolics, and other biomolecules, supporting nanoparticle formation and stabilization. Dynamic light scattering indicated a hydrodynamic size of 258.5 nm (PDI = 0.371), and zeta potential (− 7.98 mV) suggested moderate colloidal stability. In vitro assays demonstrated that the Ag–NPs exhibited notable anti-inflammatory (21.73%), anti-diabetic (36.76%), and antioxidant activity (DPPH: 78.5%; H₂O₂: 74.94%), with slightly higher performance than AgNO₃ and extract controls (<i>p</i> &lt; 0.05, ANOVA and Tukey’s HSD test).</p> Conclusion <p>This study establishes <i>Musca domestica</i> L. extract as an effective, eco-friendly bioresource for rapid green synthesis of Ag–NPs. The enhanced bioactivity of the biogenic nanoparticles underscores the importance of nanoparticle formulation in therapeutic applications. Future investigations focusing on dose–response, mechanistic insights, and cytotoxicity evaluations are warranted to fully realize their biomedical potential.</p> Graphical abstract <p></p>