This paper investigates the spatial distribution of macrozooplankton across various hydrological regions within the Southern Indian Ocean and the Southern Ocean, encompassing the Crozet and Kerguelen archipelagos in the Southern Ocean, and the islands of Saint-Paul and New Amsterdam in the Southern Indian Ocean. Data used in this study were gathered during the REPCCOAI surveys conducted during the summers from 2017 to 2019 aboard the R/V Marion Dufresne II. Macrozooplankton was collected using an Isaacs-Kidd Midwater Trawl. Taxonomic analysis revealed 248 taxa of zooplankton belonging to 20 orders. Marked differences in taxa composition were observed between the Subtropical region of the Southern Indian Ocean and the Southern Ocean because of the significant influence of hydrological fronts, such as the Subtropical Front (STF) and the Subantarctic Front (SAF), in structuring zooplankton assemblages. These differences are due to the closeness of these fronts, notably North of Crozet, where a triple front is observed, and North of Kerguelen, where the transition between the Polar Frontal Zone (PFZ) and the Subtropical Zone (STZ) is narrow.