Manganeseis currently classified as a strategic metal by many countries; consequently, understanding its geochemical behavior, distribution patterns, and metallogenic mechanisms is crucial for resource exploration and industrial applications. This paper systematically summarizes the geochemical characteristics, deposit types, metallogenic models, and resource potential of manganese, and explores the spatial distribution patterns and typical geological features of global manganese deposits. The multivalent nature of manganese (Mn2+/Mn3+/Mn4+) is discussed in detail, highlighting that its mobility and precipitation are controlled by redox conditions, pH, and temperature. Global manganese deposits are classified into four main types: marine sedimentary (including BIF- type, black shale- hosted, and carbonate- hosted deposits), supergene, ferromanganese nodule, and ferromanganese crust. Focusing on typical global manganese deposits (such as the Kalahari Manganese Field in South Africa, the Peri- Tethyan manganese district in the Black Sea region, and the Gaodi manganese deposit in China), the geological setting, genesis, and geochemistry of each type are further summarized, and the relationship between tectonic background and sedimentary environment is preliminarily discussed. Based on previous research, the formation of these deposits was largely influenced by paleo- ocean redox fluctuations during the Paleoproterozoic (Great Oxidation Event), Neoproterozoic (Neoproterozoic Oxidation Event), and Phanerozoic (alternating ice- greenhouse climates). Finally, applications in steel metallurgy, new energy batteries, agricultural fertilizers, and environmental catalysis are reviewed. The expanding new energy industry continues to drive demand for manganese- based battery materials (e. g. , lithium manganate and Ni- Co- Mn ternary materials), reinforcing the strategic significance of manganese resource development.