The issue is devoted to mesoscale and submesoscale processes in the ocean. Its topics cover various aspects of the dynamics of these processes. The geography of the researches is represented quite widely. Specifically, the comparative influence of the topography, β-effect, and the gradient of the meridional variability of the background flow on the propagation of barotropic topographic Rossby waves in the region of the Antarctic Circumpolar Current is analyzed. The seasonal variability of the thermohaline structure of cyclonic and anticyclonic mesoscale eddies in the Lofoten Basin is investigated based on satellite altimetry and a combined data that includes hydrological profiles from various platforms. The peculiarities of hydrophysical processes on the shelf and sea-level fluctuations in the Sea of Japan are studied. Inertial oscillations in the Black Sea are analyzed. The results of the theoretical study of the Ekman-type boundary layer over the anisotropic underlying surface are presented. The results of numerical modelling of the tsunami wave propagation in the Azov and the Black Seas from several seismic sources, which pose a potential hazard to the Kerch Strait, are presented. The variability of water quality in Lake Ladoga is analyzed based on satellite data. A new method for estimating the anisotropy parameters of small-scale turbulence from the data of acoustic profilers is proposed. A study of sea ice dynamics in the Pechora Sea in winter 2019/2020 is presented. A systematization of summer characteristics of short-period internal waves in the Kuril-Kamchatka region is given. Thus, the issue contains extensive material on the topic “Mesoscale and submesoscale processes in the ocean”, which will contribute to solving new problems in this area.