<p><i>Andrographis paniculata</i>, a medicinal plant species, is known for its pharmaceutical properties enriched with diterpene lactones, including andrographolides. Applying optimum irrigation regime for cultivating medicinal plants has been observed to improve water use efficiency and promote sustainable freshwater consumption. The objective of this study was to determine an optimum irrigation regime for <i>A. paniculata</i> crop using high-throughput plant phenotyping technique, which balances herbage yield and andrographolide content. <i>A. paniculata</i> plants were grown under five irrigation levels (100, 75, 50, 25, and 10% of field capacity, denoted by I₁₀₀ [control], I₇₅, I₅₀, I₂₅, and I₁₀, respectively) in pot culture, and the morphometric traits and physiological performances were assessed through high-throughput phenotyping platform and handheld measurements. Plant morphometric traits observed through digital data (canopy width, plant projected area, and plant volume) and shoot biomass (fresh weight and dry weight) were sustained under I₇₅, especially at the harvesting stage (21&#xa0;days after treatment). In contrast, a significant reduction in these parameters was observed under severe deficit irrigation (≤ I₅₀) treatments. Under severe water deficit (I₁₀), leaf greenness significantly decreased by 29% compared with the control. Consequently, osmotic potential of leaf tissues declined, especially under I₁₀ irrigation regime, which coincided with increased sucrose concentration as a major osmotic adjustment. Therefore, leaf gas exchange parameters, including net photosynthetic rate, stomatal conductance, transpiration rate, intercellular CO₂ concentration, and water use efficiency were also decreased by more than 45% (compared with the control) in plants under I₁₀; however, these parameters were retained under I₇₅ and I₅₀. Total soluble sugar, a primary product of photosynthesis, remained stable under I₇₅. Furthermore, leaf temperature and crop water stress index significantly increased under limited irrigation. Aboveground biomass, andrographolide, 14-deoxyandrographolide, total andrographolide, and andrographolide yield per plant were retained under I₇₅; however, these parameters were significantly decreased under I₁₀. I₇₅ irrigation level was identified as an appropriate irrigation for <i>A. paniculata</i>. It is recommended to provide irrigation at 75% field capacity throughout the growth period for obtaining higher leaf biomass and andrographolide yield attributes for <i>A. paniculata</i> cultivation.</p>