Mechanosensory neurons across the body have axon projections that terminate in distinct arborizations in the brain corresponding to body location. These somatotopically-organized projections provide the interface with neural circuits that direct body location-appropriate behavioral responses, such as aimed grooming. Using electron microscopy-based reconstructions, we investigate how circuits transform mechanical stimulations into location-appropriate behavior. We previously described the somatotopic organization of bristle mechanosensory neurons (BMNs) around the Drosophila head that elicit a sequence of different location-aimed grooming movements. Here, we define their complete second-order pre- and postsynaptic connectome, including interneurons, descending and ascending neurons. This identified an interneuron hemilineage whose members exhibit varied postsynaptic connectivity with BMNs from different head locations and elicit aimed grooming. Most BMN presynapses are GABAergic, consistent with hypotheses that presynaptic inhibition suppresses mechanosensory-induced grooming. This provides the first comprehensive mapping of a somatotopically organized connectome, and identifies circuit pathways that control grooming.