Biological entities such as green plants, fungi, and lichens are now a days persistently explored for the synthesis of nanoparticles. Lichen-based nanoparticles are also becoming increasingly popular owing to their biocompatibility, eco-friendliness, and cost-effectiveness. The lichen-based metal nanomaterials, particularly synthesized using green chemistry approaches, have turned out to be great substitutes to conventional antimicrobial therapies. Many scientific reports established the significant antimicrobial properties exhibited by the lichen nanoparticles. Therefore, the present mini-review summarizes an overview of lichen-based nanomaterials, their synthesis, their applications, and the molecular mechanism of their potential as broad spectrum antimicrobial agents for biomedical applications.