Purpose <p>Methyl ionone (Met), a monocyclic terpenoid, was investigated for its potential anticancer and insecticidal activity across different biological models (Human KB carcinoma cells and <i>Aedes aegypti</i>). To address Met’s limited aqueous solubility and suboptimal pharmacokinetics, copper oxide nanoparticles functionalized with polyethylene glycol (PEG) encapsulated Met (Met@PEG-CuONCs) were synthesised via chemical precipitation. </p> Methods <p>Comprehensive physicochemical characterisations suggested successful encapsulation, crystalline integrity, nanoscale morphology, and colloidal stability. The in vitro cytotoxicity assays for cell viability, induced morphological changes, generation of intracellular reactive oxygen species (ROS), and inhibition of cell cycle progression were conducted in KB cells. Similarly, larvicidal and pupicidal bioassays followed by histopathological studies on <i>Ae. aegypti</i> were conducted to examine the effect of treatment with Met and Met@PEG-CuONCs. In silico studies on Met interaction with cuticle membrane proteins were conducted through molecular docking and dynamic simulations. </p> Results <p>In vitro cytotoxicity assays against human oral carcinoma KB cells revealed that Met@PEG-CuONCs exhibited enhanced antiproliferative efficacy (IC₅₀ = 234.18&#xa0;µg/mL) compared to free Met (IC₅₀ = 472.95&#xa0;µg/mL), with induction of G₀/G₁ cell cycle arrest, increased reactive oxygen species (ROS) generation and apoptosis. The larvicidal and pupicidal activity of Met and Met@PEG-CuONCs increased markedly with concentration, resulting in significant mortality (<i>p</i> &lt; 0.001). One-way ANOVA confirmed a clear dose-response pattern for each treatment, and two-way ANOVA showed that Met@PEG-CuONCs produced significantly higher mortality than Met (<i>p</i> &lt; 0.05). Histopathological examination indicated substantial disruption of larval cuticle architecture. Molecular docking and dynamics simulations elucidated strong binding affinity and stability of Met within larval cuticle proteins, suggesting that hydrophobic and hydrogen bonding interactions may contribute to potential interactions with cuticle proteins, which suggests that MET possibly modulate the function of the cuticle protein. ADMET profiling suggested a favourable pharmacokinetic and safety profile for Met, based on in silico predictions. </p> Conclusion <p>The study highlights Met and Met@PEG-CuONCs as potential candidates for cancer therapy and vector control under laboratory conditions.</p> Graphical Abstract <p> Graphical abstract on the synthesis of Met@PEG-CuONCs for evaluation of anticancer and insecticidal properties.</p> <p></p>