The present invention relates to systems and methods for desalinating and/or treating polluted water. More particularly, the present invention relates to systems and methods for desalinating and/or treating polluted water using gas hydrates. In particular, the system comprises a desalination tank configured to form gas hydrates using a suitable hydrate former taken from a storage tank that is operatively connected to the desalination tank. With all operations, including formation of gas hydrates, discharging of highly saline water, washing the gas hydrates and dissociation of gas hydrates being conducted in a single pressurized tank such as the desalination tank, the present apparatus provides a simple and efficient solution at a low manufacturing and operating cost.