Carbonyl sulfide (OCS) is a major precursor of stratospheric sulfate aerosols and a proxy for terrestrial photosynthesis. In recent years, sulfur‐isotope measurements (δ 34 S) of OCS emerged as an approach to constrain the OCS budget. Yet, such measurements are still scarce for aquatic OCS. Here we present a large dataset of δ 34 S values of marine OCS. In addition, we present δ 34 S values of marine carbon disulfide (CS 2 ) a...