<p>High salinity negatively impacts plant growth and productivity. However, the use of plant growth regulators has emerged as an effective strategy to enhance plant resilience under saline conditions. Among these, Triacontanol (TRIA) has gained attention for alleviating negative impacts of salinity via ameliorating the biochemical and physiological responses. While it has been studied primarily in cereals and vegetable crops, its potential for fruit crops remains unexplored. Therefore, the current study was conducted to evaluate its impact on guava (<i>Psidium guajava</i>) under saline stress conditions (16.0 dS m⁻¹). We specifically evaluated the impact of two TRIA concentrations (1.0, 2.0 mg/L) on growth, physiology and biochemical traits of four different guava genotypes (‘Sadabahar Sufaid Gola’ [SSG], ‘Apple Guava’ [AG], ‘Surahi’ and ‘Sufaida’). Results demonstrated that TRIA improved the growth traits of all the studied guava genotypes; however, AG and SSG depicted significant results compared to ‘Surahi’ and ‘Sufaida’ genotypes under saline and non-saline conditions. Both the TRIA concentrations improved plant growth traits, but 1.0 mg/L produced more promising results for the fresh and dry biomass of the plant. Additionally, significant differences were recorded for gas exchange parameters including stomatal conductance, transpiration rate and photosynthetic rate under saline conditions. Similarly, enzymatic activities (superoxide dismutase [SOD], peroxidase [POD], catalase [CAT]) and malondialdehyde accumulation was increased under saline conditions; however, TRIA (1.0 and 2.0 mg/L) improved all these traits. Overall, this study highlights the promising role of TRIA to enhance salinity tolerance in young guava plants.</p>