The world’s total water supply is enormous compared with the presently conceivable needs of man, yet there is a growing water concern. Approximately 98% of the 320 million cubic miles of water in the Earth’s crust is salty and useful neither for irrigation by present techniques nor for the majority of man’s other needs. An obvious way to increase water availability is to recover freshwater through desalination from seawater or from the large underground stores of brackish water, which are available in many arid regions. This chapter introduces the reader to the desalination process. Traditional processes are reviewed and 11 new options for desalination are presented. These include solar evaporation, crystallization, a greenhouse solar evaporator, a simple evaporation (still) unit, a humidification/dehumidification unit, a heat conduit evaporator, a geothermal evaporator, freeze desalination process, mangrove processes, a humidification unit, and reverse osmosis and crystallization hybrid processes. An application section provides three Illustrative Examples related to the general subject of water desalination options.