Due to the increasing population, economic development, and climate change, providing food and water security requires significant changes in the technologies that propel present-day water management. Irrigation is the largest and most inefficient water user, and there is an expectation that even small improvements in agricultural water productivity will enhance water security. Increasing water productivity is a novel practice needed to improved water management for sustainable agriculture, food security and healthy ecosystem. The explanation of water productivity involves the quantity of agricultural output per unit of water loss, which can be applied to crops, livestock and aquaculture. This chapter reviews the challenges and opportunities for enhancing water productivity in socially equitable and sustainable ways. Water productivity can be improved in irrigated and rainfed cropping systems by choosing a well-adopted crop type, reducing unproductive water losses, and maintaining healthy, vigorous growing crops through optimized water, nutrient, and agronomic management. Livestock water productivity can be increased through improved feed management and animal husbandry, reduced animal mortality, appropriate livestock watering, and sustainable grazing management. In aquaculture systems, most water is lost indirectly for feed production via seepage and evaporation from water bodies, and through polluted water discharge, and efforts to improve water productivity should be directed at minimizing those losses. The review also identifies different strategies for improving agricultural water productivity and biophysical and climate change influence on agricultural water productivity. Effort has been made to address why agricultural water productivity matters.