<p>Irrigation water containing thiocyanate (SCN⁻) has detrimental effects on plant growth and yield. However, hydrogen sulfide (H₂S) acts as a crucial signaling molecule, enhancing plant resistance to SCN⁻ stress. To explore the impact of exogenous H₂S on early rice plant growth under SCN⁻ stress, a hydroponics-based experiment was conducted, focusing on the interactions between exogenous H₂S and endogenous plant hormones. The study revealed significant alterations in levels of key hormones (ACC, IAA, JA, CKs) in both rice roots and leaves under SCN⁻ stress. Thiocyanate stress notably increased ACC levels in roots, which were mitigated by exogenous H₂S, while its influence on leaves was minimal. Thiocyanate exposure had a substantial effect on IAA levels in roots, which were significantly increased by exogenous H₂S. Furthermore, thiocyanate stress led to increased JA levels in roots and shoots but decreased CKs levels in roots. Treatment with exogenous H₂S further intensified these trends. Principal component analysis (PCA) and Kohonen’s self-organizing map (SOM) analysis demonstrated that H₂S exhibited an antagonistic effect on CKs and ethylene, while synergistically influencing IAA and JA levels under SCN⁻ stress. This study provides novel insights into the regulation of plant hormone levels in rice seedlings by exogenous H₂S, facilitating enhanced resistance to SCN⁻ stress and promoting sustainable agriculture.</p>