<p>A comprehensive understanding of iron (Fe) dynamics in soil acidification processes is crucial for formulating effective and site-specific liming strategies in acid soils. The study investigated the dynamics of Fe fractions, interrelations with acidity and the stability of Fe minerals in the hydromorphic paddy soils of Kerala, India. Georeferenced composite soil samples were collected from rice-growing agroecological units of Kerala during April to May 2023. The soil samples were subjected to sequential extraction of Fe fractions: F_ws, water-soluble and exchangeable; F_sp, specifically adsorbed lead (Pb) displaceable; F_as, acid-soluble; F_mn, manganese (Mn) oxide-occluded; F_om, organic matter occluded; F_am, amorphous Fe oxide-occluded; F_ci, crystalline Fe oxide-occluded and F_rs, residual. Besides, the forms of acidity were also analysed to determine A_ex, exchange acidity; A_et, extractable acidity; A_ta, total acidity; A_tp, total potential acidity; and A_pd, pH-dependent acidity. Path analysis (<i>p</i> = 0.05) revealed that F_as had a significant direct positive influence (0.82), and F_wa had a significant direct negative effect (−&#xa0;0.53) on pH. The changes in F_as were directly controlled by F_mn and that of F_wa by F_sp. The A_et had a direct positive, and A_tp had a significant negative control (−&#xa0;1.16) on A_ex in the soil. Structural equation modelling revealed a significant negative effect between F_sp and a positive direct effect between F_as, F_om and F_ci on A_et. The F_as imposed a significant direct positive and F_am, a significant negative control on A_tp. Thus, acid soluble Fe, extractable acidity, and total potential acidity were found to be the influencing factors of pH in the paddy soils of Kerala. Further, the mineral stability diagram of Fe revealed that the solubility of Fe was controlled by amorphous Fe minerals in the paddy growing hydromorphic wetlands of Kerala, India.</p>