The GLORYS (Global Ocean reanalysis and Simulation) Project is motivated by the need of a realistic description of the ocean state and variab ility over the recent decades, at the global scale, and at the scale of the ocean basins and regional s eas ( https://reanalyses.org/ocean/overviewcurrent-reanalyses ). The French research community (CNRS), the operat ion l ocean forecasting center MERCATOR-Ocean ( http://www.mercator-ocean.fr ) and the CORIOLIS data center (http://www.coriolis.eu.org/ ), have gathered their skills and expertise in phys ical oceanography, ocean modeling and data assimilation, to carry out global ocean reanalyses at eddy scale resolution for the period 1992 to present. This rea nalysis effort is part of the project MyOcean granted by the European Commission within the GMES Program (7th Framework Program, http://www.myocean.eu/ ).