Galleria mellonella is an established invertebrate model for studying host-pathogen interactions and immune responses. Although cytokine-analogous proteins are crucial for immune regulation in both vertebrates and invertebrates, their roles in insects remain poorly understood. This study examines the involvement of an IL-19-like protein in G. mellonella immunity, particularly in response to fungal infection and immune modulation. It uses proteomic analysis, fluorescence microscopy, flow cytometry and ELISA to determine the presence of IL-19-like protein in G. mellonella hemocytes following Conidiobolus coronatus infection and exposure to the fungal metabolites harman and norharman. It also assesses the effects of recombinant IL-19 on selected functions of wax moth hemocytes. This study provides the first proteomic confirmation of an IL-19-like protein in G. mellonella, and confirms its increased expression after C. coronatus infection. Harman and norharman treatment further elevated IL-19-like protein levels in hemocytes. Functionally, IL-19 promoted hemocyte migration, network formation, and wound healing while inhibiting ROS production but did not affect apoptosis, phagocytosis or fungal susceptibility. IL-19 also upregulated Jak1- and Jak2-like proteins, indicating its involvement in JAK-STAT signaling. Our findings highlight the evolutionary conservation of cytokine-like proteins and their immunomodulatory roles in insects. They reinforce the utility of G. mellonella as a model for cytokine research and fungal pathogenesis, and provide new insights into IL-19-like proteins in immune regulation.