This paper reviews the mineralogical and chemical characteristics of clays found in southern part of Nigeria, with a view to determine its usability. The usability of clays, depends on its chemical and mineralogical charactertics, the end product of clay after it is been processed is also based on it’s charactertics. From reviewed literature, it was observed that sampled clay within the study area were analyzed using the XRD, XRF and ICPMS method. Further findings also revealed that the dominant clay minerals within the study area include montmorillonite, illite, and kaolinite. On the other hand, it was observed that non-clay minerals such as feldspar, quartz, dickite and many others were found with clay as revealed by several scholars. While chemical charactertics of clay consists mainly of Al2O3, K2O, CaO and SiO2, with other major oxides such as P2O5, MgO, Fe2O3, TiO2, MnO and Na2O. Some trace elements such Be, Ba, Sc, Sr, Zr, V and Y were reported to be present in clays deposit found in selected part of Ogun state. From reviewed articles, it was observed that mineralogical and chemical charactertics of clay make it suitable for pharmaceutical, textile, cosmetic and polymer industries, but considered to be fairly suitable for oil and gas industry.