Dhaka is one of the fastest-growing megacities in Asia, where the urban population is increasing noticeably. Currently, the megacity is home to more than 21 million people, with the average annual growth rateGrowth rate of the population is 4.2% annually. By 2030, the city's population is expected to reach about 28.1 million. The growing urban population creates an enormous load on the city's existing infrastructures and amenities. This chapter summarizes the urbanizationUrbanization trend in Dhaka city, the status of water supplyWater supply and sanitationUrbanization sanitation services, existing infrastructural facilities, and significant challenges and prospects towards ensuring sustainable water supplyWater supply and sanitation in light of the United Nation's sustainableDevelopment development goal (SDG). The study shows that the rapid urbanization process in Dhaka city creates tremendous pressure on the city's infrastructure and essential services, including water supply and sanitation. Moreover, due to resource constraints, inadequate infrastructures, and lack of coordination in the service sector, it is challenging to ensure adequate water supply and sanitation services. However, considerable progress has been observed mainly in the city's water supply sector, including several projects and plans that have already commenced to comply with the SDG in the water supplyWater supply and sanitation sector.