The use of Galleria mellonella, or the greater wax moth larva, as a model organism for toxicology assessments of nanomaterials offers a promising bridge between in vitro and in vivo studies. Traditional in vitro models often fail to replicate complex biological responses, while in vivo studies are costly and raise ethical concerns. The shared similarities of insect and mammalian innate immune systems has enabled the use of G. mellonella as an effective infection model to study host-pathogen interactions without the ethical issues associated with vertebrates. Recent studies indicate that G. mellonella can effectively mimic human immune responses, making it suitable for assessing the biocompatibility and toxicity of various nanomaterials, including carbon nanotubes and metal nanoparticles. Its immunological characteristics make it particularly valuable for immunotoxicity studies, helping to evaluate the impact of nanomaterials on immune responses. This innovative approach not only streamlines the assessment process but also aligns with the principles of the 3Rs (Replacement, Reduction, Refinement) in toxicology research. As research in nanotechnology progresses, further development of the G. mellonella model could play a pivotal role in ensuring the safe development and application of nanomaterials and in enhancing our understanding of host-pathogen dynamics and immunotoxicity.