<p>Excessive application of copper (Cu)-based agrochemicals is a major source of Cu contamination in the soil, leading to Cu toxicity in crop species. Biochar is an effective soil amendment for remediation of metal contaminants. The aim of this study was to assess the impacts of rice husk biochar on Cu uptake, physio-biochemical responses, growth characteristics, and yield attributes of Riceberry rice (<i>Oryza sativa</i> L.) under Cu treatments. Two-week-old rice seedlings were directly transplanted into plastic bags containing soil substrate mixed with 0% (control) and 1% (w/w) rice husk biochar. After 14 days of transplanting, rice plants were exposed to CuSO₄ treatments at concentrations of 0 μM (control), 75 μM, and 150 μM for two months. Under 75 and 150 μM Cu treatments, Cu concentrations in root tissues were significantly increased, whereas Cu was not detected in the control plants. However, low Cu concentrations in leaf tissues were detected even under excess Cu treatment, indicating restricted translocation of Cu from roots to shoots. Plants treated with exogenous Cu exhibited increased levels of calcium (Ca²⁺) and magnesium (Mg²⁺) ions in leaf tissues. The biochar application resulted in a reduction of chlorophyll pigment and net photosynthetic rate, and an increase in the accumulation of ascorbic acid and total tocopherol as major antioxidant compounds. In addition, the number of leaves and shoot dry weight of plants treated with 150 μM Cu and biochar increased, leading to improved panicle length, panicle weight, number of grains, and total grain weight. These findings indicate that soil amendment with biochar is a promising strategy for Cu immobilization, modulating antioxidant compounds and improving growth and productivity of Riceberry rice under Cu treatments.</p>