The Global Ocean Multi Observations OMEGA3D product has been developed by the Consiglio Nazionale delle Ricerche in the framework of the Copernicus Monitoring Environment Marine Service (CMEMS). It provides a timeseries of 3D quasi-geostrophic vertical and horizontal ocean currents covering the period from January 1993 to December 2018. The data are provided over a regular grid at 1/4° horizontal resolution, with 75 non-uniformly spaced vertical levels between the surface and 1500 m depth. OMEGA3D product is delivered with a weekly sampling (representative of each Wednesday). The velocities are obtained by solving a Q-vector formulation of the Omega equation that explicitly considers the effect of both geostrophic advection and upper layer turbulent mixing as described by KPP parameterization. Omega forcings are estimated from the CMEMS observation-based ARMOR3D temperature and salinity multi-year data and ERA-Interim surface fluxes.