Water scarcity is a major challenge facing agriculture, particularly in arid and semi-arid regions, highlighting the need for innovative water-management strategies. Delayed irrigation is a scheduling strategy based on planned postponement of irrigation relative to the reference time, considering crop growth stage and sensitivity. This study reviewed national and international research on the effects of delayed irrigation on crop yield, water consumption and productivity, physiological responses, and selected environmental outcomes, while identifying factors affecting its effectiveness. A systematic review was conducted using ScienceDirect, Google Scholar, SID, Magiran, and Civilica. Following screening, more than 50 relevant articles published during the past 25 years were selected. Data on crop type, growth stage, delay intensity and duration, irrigation method, water consumption, yield, water productivity, and physiological responses were extracted and synthesized descriptively and analytically. Results showed that, unlike regulated deficit irrigation, which mainly reduces the amount of water applied, delayed irrigation focuses on irrigation timing and intervals between irrigation events. Crop responses depended strongly on crop type, growth stage, delay intensity and duration, climatic conditions, soil moisture, and complementary management practices. Under suitable conditions, delaying irrigation during less sensitive growth stages and within crop tolerance limits reduced water consumption or improved water productivity while maintaining acceptable yields. Mild stress was associated with changes in root development, stomatal regulation, and osmotic adjustment, whereas severe or prolonged delays could reduce growth and yield. Some studies also reported reduced methane emissions in rice and improvements in soil indicators. Water savings of approximately 20–30% without noticeable yield reduction and, under favorable conditions, yield increases of 10–40% with improved water productivity have been reported; however, these ranges are not universally applicable. Overall, delayed irrigation can support integrated water management and improve water productivity when appropriate timing, crop tolerance thresholds, monitoring, and complementary practices are considered.