Carbonyl sulfide (OCS) was initially reported by Jefferts et al. in 1971. The first detection was made via a single rotational line observed in Sgr B2. A second, confirming line was reported several years later, by Akabane et al. By 1981, OCS had been observed in ten interstellar and circumstellar sources by means of seven different rotational lines. The first extragalatic detection was reported by Mauersberger et al. in NGC 253. Finally, OCS has been found in the solar system in atmosphere of Venus and in several comets, beginning with Hyakutake in 1997. It is produced naturally on Earth from "volcanoes, marshes, soils, and deciduous and coniferous trees."

OCS is also one of the comparably small number of molecules that have been observed in interstellar ices.

While the bonding in carbonyl sulfide is similar to that of carbon dioxide, it has a dipole moment.