<jats:title>Abstract</jats:title><jats:p>Opsins, light-sensitive G protein-coupled receptors, have been identified in corals but their properties are largely unknown. Here, we identified six opsin genes (acropsins 1–6) from a coral species <jats:italic>Acropora millepora</jats:italic>, including three novel opsins (acropsins 4–6), and successfully characterized the properties of four out of the six acropsins. Acropsins 1 and 6 exhibited light-dependent cAMP increases in cultured cells, suggesting that the acropsins could light-dependently activate Gs-type G protein like the box jellyfish opsin from the same opsin group. Spectral sensitivity curves having the maximum sensitivities at ~ 472 nm and ~ 476 nm were estimated for acropsins 1 and 6, respectively, based on the light wavelength-dependent cAMP increases in these opsins-expressing cells (heterologous action spectroscopy). Acropsin 2 belonging to the same group as acropsins 1 and 6 did not induce light-dependent cAMP or Ca<jats:sup>2+</jats:sup> changes. We then successfully estimated the acropsin 2 spectral sensitivity curve having its maximum value at ~ 471 nm with its chimera mutant which possessed the third cytoplasmic loop of the Gs-coupled jellyfish opsin. Acropsin 4 categorized as another group light-dependently induced intracellular Ca<jats:sup>2+</jats:sup> increases but not cAMP changes. Our results uncovered that the <jats:italic>Acropora</jats:italic> coral possesses multiple opsins coupling two distinct cascades, cyclic nucleotide and Ca<jats:sup>2+</jats:sup>signaling light-dependently.</jats:p>