Mosquitoes transmit pathogenic flaviviruses such as dengue (DENV), Zika (ZIKV), and West Nile (WNV) viruses. Current vector interventions remain incompletely effective and vaccines have safety concerns, emphasizing the need for novel strategies. Viruses exploit the host lipids for amplification. Bite-initiated skin infection is a bottleneck in transmission and therefore an interesting target for new interventions. My study aims at characterizing the lipid response in bitten skin to identify transmission-blocking targets. Applying lipidomics to an in-vivo mouse model of mosquito-mediated transmission, I first observed that bite upregulates ceramides in skin. Cutaneous ceramide upregulation was confirmed by targeted and kit-based quantification. Second, I used in-vitro and in-vivo approaches to identify the enzymes responsible for the ceramide upregulation. Third, I applied in-vitro gene silencing and ceramide supplementation to demonstrate that ceramides possess antiviral activity conserved across flaviviruses such as WNV, DENV, and ZIKV. Fourth, I showed that ceramides specifically alter viral attachment. Finally, I depleted the identified enzymes in the mouse skin to show that cutaneous ceramide upregulation reduces flaviviral transmission. This study elucidates the regulation of skin lipids, identifying ceramides as an antiviral lipid-based response which can be harnessed for topical transmission-blocking interventions. Keywords: mosquito-borne viruses, flavivirus, ceramides, lipidomics, viral transmission