<p>Salinity severely affects the growth of rice (<i>Oryza sativa</i> L.), particularly during the seedling stage. Seed priming with different chemicals has shown potential to mitigate salinity stress in various crops; however, limited information exists for rice grown under flooded, lowland conditions. This study evaluated (i) the most effective concentrations of selected priming agents for rice germination and (ii) their efficacy in improving seedling growth under different soil salinity levels. Priming agents included calcium chloride (CaCl₂), magnesium chloride (MgCl₂), gibberellic acid (GA₃), mannitol, sodium nitroprusside (SNP), and zinc sulfate (ZnSO₄), each tested at five concentrations with distilled water as control. The optimal concentrations promoting germination were 10, 1, 0.025, 30, 0.031, and 2.5&#xa0;g L⁻¹ for CaCl₂, MgCl₂, GA₃, mannitol, SNP, and ZnSO₄, respectively. A pot experiment was conducted using these concentrations under three salinity levels-very low (0.1 dS m⁻¹), low (0.2 dS m⁻¹), and moderate (0.6 dS m⁻¹)-and a non-saline control, using the salinity-susceptible variety Bg300. After two weeks, ZnSO₄ priming at very-low salinity enhanced seedling growth by 73% (P &lt; 0.05). Mannitol, SNP, and ZnSO₄ also increased shoot K⁺ concentration compared with hydro-primed seedlings (P &lt; 0.05), contributing to ionic homeostasis. At low salinity, CaCl₂ and mannitol priming reduced Na⁺ uptake by 68% and 73%, respectively (P &lt; 0.05), alleviating sodium toxicity though without significant growth improvement (P &gt; 0.05). Thus, ZnSO₄ seed priming appears to be a cost-effective strategy to enhance early growth of salinity-susceptible rice in very-low saline lowland soils. Further research should evaluate its field-level performance and adaptability.</p> Graphical Abstract <p></p>