The intensification and extension of agriculture have highly contributed to the global food production in the last five decades. However, intensification without due attention to ecosystem services and sustainability of soil and water resources has contributed to land and water quality degradation such as soil erosion, decreased soil fertility and quality, salinization and nutrient discharge to surface and ground waters. Land use change from forests to crop lands has altered the vegetation pattern and hydrology of landscapes with increased nutrient discharge from crop lands to riverine environment. Global climate change will increase the amount of water required for agriculture in addition to water needed for additional irrigation development causing water scarcity in many dry, arid and semi-arid regions. The water and nutrient use efficiencies of agricultural production systems are still below 40 % in many regions across the globe. Nitrogen (N) and phosphorus (P) fertilizer use in agriculture have accelerated the cycling of these nutrients in the landscape and contributed to water quality degradation. Such nutrient pollution has a wide array of consequences including eutrophication of inland waters and marine ecosystems. This chapter reviews major factors and drivers that affect water dynamics and nutrient pollution in agricultural landscapes. Water flux is the main driver of nutrient pollution and is influenced by land use (vegetation), soil physical and chemical characteristics and climate change. Appropriate land and water management practices that include irrigation scheduling and conservation practices are important for improving downstream water quality, quantity and the environmental services provided by the water. This approach can reduce agricultural water use by up to 65 % in arid and semi-arid irrigation areas. While fertilizer N and P for agriculture increased by 10 and 14 % respectively between 2010 and 2015, crop nutrient use efficiencies, of 25-65 % and 10-30 % for N and P respectively, were still low leading to losses of N and P from agricultural landscapes. Fertilizer and manure application together with legumes cropping contributed almost 60 % N and 69 % P to surface water systems from landscapes. Assessment of soil water, crop water and nutrient use, water losses by evapotranspiration (ET) and soil evaporation and their spatial and temporal variations is important for integrating field losses to landscape scale and to help develop management strategies for improving water quality and quantity of the landscape. A number of techniques such as ground based monitoring, remote sensing and isotopic, are available for assessments. This will provide opportunities to identify target areas for changing land use to improve water and nutrient use efficiencies, food security, reduce water quality degradation and enhance eco-system services of agricultural landscapes.