Potable reuse is becoming an increasingly common strategy for bolstering water resource portfolios in water-scarce regions. Each application poses unique challenges, whether related to treatment goals, regulatory requirements, or political and public acceptance, and these issues have a significant impact on the final treatment train selection. This review describes the various potable reuse frameworks and illustrates the importance of environmental buffers as a treatment barrier and as a distinction between ‘indirect’ and ‘direct’ potable reuse applications. This review also highlights more than 20 potable reuse treatment trains currently in operation or under construction throughout the world. The unit processes in each train are identified and a brief summary of their advantages and limitations in relation to alternative processes is included.