Galleria mellonellais a promisingin vivomodel insect used for microbiological, medical, and pharmacological research. It provides a platform for testing the biocompatibility of various compounds and the kinetics of survival after an infection followed by subsequent treatment, and for the evaluation of various parameters during treatment, including the host–pathogen interaction. There are some similarities in the development of pathologies with mammals. However, a limitation is the lack of adaptive immune response. Antimicrobial photodynamic therapy (aPDT) is an alternative approach for combating microbial infections, including biofilm-associated ones. aPDT is effective against Gram-positive and Gram-negative bacteria, viruses, fungi, and parasites, regardless of whether they are resistant to conventional treatment. The main idea of this comprehensive review was to collect information on the use ofG. mellonellain aPDT. It provides a collection of references published in the last 10 years from this area of research, complemented by some practical experiences of the authors of this review. Additionally, the review summarizes in brief information on theG. mellonellamodel, its advantages and methods used in the processing of material from these larvae, as well as basic knowledge of the principles of aPDT.