Nanoclay has a great potential in various fields. Small amount of nanoclay can change the whole physical and chemical properties of polymers, paints, inks and lubricants by dispersing nanoclay layers into the polymer matrices. The flexibility of interlayer gallery of nanoclay helps in the release of drugs to the targeted place. The controlled release of drugs takes place on account of the drug incorporated within the nanoclay galleries. This makes these nanomaterials as potential materials with its application in pharmaceutical field. Organoclays, a type of nanoclay are also being utilized for waste water treatment in junction with other sorbents viz. activated carbon and alum. Organoclays have been found to be the finest material for water treatment especially when the water contains enough amounts of oil and grease or humic acid. The use of nanoclays as reinforcing agent or additives in polymers for various properties is exploited for various applications. This chapter provides an overview of nanoclays or types of nanoclays with significance on the utilization of nanoclays as the filler in polymer matrices for the synthesis/fabrication of polymer nanocomposites, drug delivery agents, viscosity modifier for coatings, inks and lubricants and nanoclays for industrial effluent as well as potable water treatment. © 2016, Springer Science+Business Media Singapore.