Water and nitrogen are widely used agricultural inputs in potato production areas. However, the excessive and inappropriate use of these significant inputs may lead to the rapid depletion of water resources and inappropriate nitrogen leakage. In potato production, insight into the effects of water and nitrogen on the physiological properties will help to overcome these difficulties. This study was therefore conducted to determine the effects of different nitrogen and irrigation levels on the physiological (photosynthesis rate, leaf area index, leaf chlorophyll content, and leaf temperature) characteristics of potato. Field experiments were conducted during the 2021–2022 and 2022–2023 primary potato cropping seasons to select the suitable combination of irrigation and fertilization levels for potato production in the Nigde Province of the Central Anatolia Region of Turkey. Employing a factorial design, the study encompassed six nitrogen fertilization rates and three irrigation levels. Measurements were systematically recorded at five distinct intervals (40, 50, 60, 70, and 80 days) post-emergence. The outcomes underscored that nitrogen treatments augmented physiological traits, manifesting in heightened photosynthetic rates, chlorophyll content, and leaf area indices, barring leaf temperature, in comparison to the control group (devoid of nitrogen treatments). Full irrigation (I1) yielded the utmost values for both photosynthesis and leaf area index, with I1N3 (full irrigation and intermediate nitrogen supply) was identified as the most efficacious treatment for these parameters. This study identifies the most appropriate nitrogen and irrigation application for optimum physiological yield of the potato for crop producers. However, it is important to note that the study focused solely on one commercial potato cultivar (Agria), and further research on various potato cultivars is recommended for more conclusive results.