Insect chemoreception is mediated by a large and diverse superfamily of seven-transmembrane domain receptors. These receptors were first identified in Drosophila, but have since been found in other insects, including mosquitoes and moths. Expression and functional analysis of these receptors have been used to identify receptor ligands and to map receptors to functional classes of neurons. Many receptors detect general odorants or tastants, whereas some detect pheromones. The non-canonical receptor Or83b, which is highly conserved across insect orders, dimerizes with odorant and pheromone receptors and is required for efficient localization of these proteins to dendrites of sensory neurons. These studies provide a foundation for understanding the molecular and cellular basis of olfactory and gustatory coding.