The efficient conversion of CO₂ to formic acid (FA) in an aqueous medium remains challenging due to the use of expensive catalysts, high reaction temperatures, and low FA selectivity. In this study, the non-catalytic reduction of CO₂ to FA using NaBH₄ as an in-situ hydride donor was systematically investigated. Under the optimized reaction conditions (1 g NaBH₄, 0.5 g NaOH, ambient temperature, 30 bar CO₂, 1 h), ~100% FA selectivity with a maximum FA yield of ~0.97 M was achieved. The addition of NaOH effectively controlled the hydrolysis of BH₄^- to B(OH)₄^-, which increased the FA formation from 65 wt% to 77 wt%. The reaction pathway for FA formation was proposed and validated using ¹H and ¹¹B NMR analyses. In addition, an artificial neural network (ANN) model accurately predicted FA yield (R² >0.99), offered a more accurate and reliable approach for process parameters prediction. Overall, this study demonstrated a simple, efficient, and highly selective non-catalytic pathway for the CO₂ hydrogenation to FA using NaBH₄ as a hydrogen source in an aqueous medium.