Animals mimicking other organisms or using camouflage to deceive predators are vital survival strategies. Modern and fossil insects can simulate diverse objects. Lichens are an ancient symbiosis between a fungus and an alga or a cyanobacterium that sometimes have a plant-like appearance and occasionally are mimicked by modern animals. Nevertheless, lichen models are almost absent in fossil record of mimicry. Here, we provide the earliest fossil evidence of a mimetic relationship between the moth lacewing mimic Lichenipolystoechotes gen. nov. and its co-occurring fossil lichen model Daohugouthallus ciliiferus. We corroborate the lichen affinity of D. ciliiferus and document this mimetic relationship by providing structural similarities and detailed measurements of the mimic’s wing and correspondingly the model’s thallus. Our discovery of lichen mimesis predates modern lichen-insect associations by 165 million years, indicating that during the mid-Mesozoic, the lichen-insect mimesis system was well established and provided lacewings with highly honed survival strategies.