Abiotic stresses, such as drought, salinity, and temperature fluctuations, are significant factors limiting plant growth and productivity worldwide. In response, plant growth regulators have gained attention for their potential in enhancing plant resilience to these stresses. Triacontanol (TRIA), a long-chain alcohol, has emerged as a promising PGR capable of mitigating the adverse effects of environmental stress on plants. This review explores the physiological, biochemical, and molecular mechanisms underlying the beneficial effects of TRIA on plant growth and development, particularly in stressed conditions. The application of TRIA has been shown to enhance stress tolerance by improving photosynthetic efficiency, boosting antioxidant enzyme activity, modulating osmotic balance, and stimulating nutrient uptake. Additionally, TRIA promotes the synthesis of compatible solutes and regulates stress-responsive gene expression, leading to improved plant health and yield. The review also highlights the broader applications of TRIA in agriculture, from improving crop quality and productivity to enhancing resistance to environmental stressors. Furthermore, we examine TRIA’s interactions with other plant hormones and its potential to complement sustainable agricultural practices in mitigating climate change impacts. Given its broad potential, TRIA represents a promising tool for enhancing agricultural productivity and sustainability in the face of global environmental challenges.