This paper presents a review of long-term (2001–2018) original studies of the algae flora of the hyperhaline Kuyalnyk estuary, 6 tributaries flowing into it (rivers, streams, water channels from ponds), ephemeral reservoirs located along the estuary and 5 adjacent reservoirs of different types (ponds, reservoirs). The features of distribution algae species in Kuyalnyk estuary and distribution of these organisms in the water bodies of the estuary basin, as well as the main environmental factors influencing the formation of their species composition are analyzed. A total of 270 species (274 ist) of algae (phytoplankton, micro- and macrophytobenthos, periphyton) from 9 divisions (<i>Cyanoprokaryota </i>– 45 species (46 ist), <i>Bacillariophyta</i> – 159 species (161 ist), <i>Chlorophyta </i>– 37 species (38 ist), <i>Euglenophyta</i> – 16 species, <i>Charophyta </i>– 7 species, <i>Chrysophyta</i> – 3 species, <i>Xanthophyta</i>, <i>Dinophyta</i> and <i>Haptophyta </i>– 1 species each. Diatom algae (<i>Bacillariophyta</i>) – 61 species (82% of the total number of species found in each of the studied reservoirs) with a predominance of species of the genus <i>Navicula</i> prevail in terms of species richness in the algae flora of the estuary basin. Second and third places are shared by <i>Cyanoprokaryota</i> and <i>Chlorophyta</i>. At the time of the study, 18 species of macrophytes were identified in these water bodies. A number of identified species are characterized by high physiological fitness and rapid response to changes in environmental conditions: <i>Phormidium breve</i> (Kütz. ex Gomont) Anagn. et Komárek, <i>Spirulina major</i> Kütz., <i>S. meneghiniana</i> (Zanardini ex Gomont) W.B.Grow, <i>Cyclotella meneghiniana</i> Kütz., <i>Ctenophora pulchera</i> (Raits ex Kütz.) D.M.Williams ex Round, <i>Rhoicosphenia abbreviata</i> (C.Agardh.) Lange-Bert., <i>Tabularia tabulata</i> (C.Agardh) Snoeijs, <i>Ulnaria ulna</i> (Nitzsch.) Compere, <i>Achnanthes brevipes</i> C.Agardh var <i>brevipes</i>, <i>Platesa salinarum</i> (Grunow) Lange-Bert., <i>Fallacia pygmaea</i> (Kütz.) Stick et D.G.Mann, <i>Navicula cryptocephala </i>Kütz., <i>N. gregaria</i> Donkin, <i>Bacillaria paxillifera</i> (O.Müll.) T.Marsson, <i>Cylindrotheca closterium</i> (Ehrenb.) Reimann et G.C.Levin, <i>Tryblionella apiculata</i> W.Greg., <i>T. hungarica</i> (Grunow) Frenguelli, <i>Surirella striatula</i> Turpin, <i>S. minuta</i> Bréb. ex Kütz., <i>Dunaliella Salina</i> (Dunal) Teodor. Mineralization as a factor influencing the structure of algal communities is most severe in the Kuyalnyk estuary, in the confluence of the tributaries and estuaries, controlling the composition of dominant species.