Leakage in water distribution systems (WDSs) causes problems such as water pollution, land subsidence, water waste, service interruption, water distribution inequity, increasing cost of operation and maintenance, and revenue and energy losses. To control the leakage level, a proactive strategy such as leakage detection is necessary to find, detect, and fix leaks in WDSs. Leakage can be detected in several different ways, including by sensors, which are widely used in the literature to detect leaks and reduce water loss. The deployment of sensors is determined by several objectives, which should be formulated in such a way that the trade-off between the objectives results in a satisfactory compromise. Moreover, water utilities seek ways to reduce leak detection time and costs. Therefore, this chapter discusses the methods, developments, and applications of optimal deployment of sensors for leakage detection using metaheuristic algorithms, in which various computational frameworks are used.