This review paper discusses the multifaceted roles of salicylic acid (SA) in plant growth and development, beyond its well-known function in plant defense against pathogens. SA is not only involved in mediating responses to biotic and abiotic stresses but also plays a crucial role in various physiological and biochemical processes throughout a plant's life cycle. The paper highlights SA's involvement in seed germination, photosynthesis, respiration, growth, flowering, and senescence. SA affects seed germination in a concentration-dependent manner. High concentrations of SA can inhibit germination by inducing oxidative stress, while low concentrations can improve germination under abiotic stress conditions by reducing oxidative damage. SA also interacts with other plant hormones such as abscisic acid (ABA) and gibberellins (GAs) to regulate germination. In terms of photosynthesis, SA can both inhibit and enhance photosynthetic activity depending on its concentration. It affects leaf and chloroplast structure, stomatal closure, chlorophyll content, and enzyme activities like RuBisCO and carbonic anhydrase. SA also provides protection against oxidative stress induced by herbicides and heavy metals. Regarding respiration, SA influences the alternative oxidase (AOX) pathway, which is important for maintaining redox homeostasis and ATP synthesis. It can either stimulate or inhibit respiration depending on its concentration, and it affects mitochondrial function by altering electron transport and oxidative phosphorylation. SA's role in plant growth is complex, with evidence suggesting it can both promote and inhibit growth. Mutant and transgenic plants with altered SA levels exhibit various growth phenotypes, indicating SA's regulatory role in growth processes. SA also interacts with other signaling pathways, such as those involving the mitogen-activated protein kinase (MAPK) cascade, to regulate growth and development. In flowering, SA has been shown to induce flowering in various plant species. It interacts with photoperiod and autonomous pathways, influencing the expression of key flowering genes such as FLC, CO, and SOC1. SA also plays a role in senescence by regulating the expression of senescence-associated genes (SAGs) and interacting with the WRKY53 transcription factor and jasmonic acid (JA) signaling pathway. Overall, SA is a key signaling molecule that integrates multiple physiological processes in plants, contributing to their health, development, and response to environmental challenges.This review paper discusses the multifaceted roles of salicylic acid (SA) in plant growth and development, beyond its well-known function in plant defense against pathogens. SA is not only involved in mediating responses to biotic and abiotic stresses but also plays a crucial role in various physiological and biochemical processes throughout a plant's life cycle. The paper highlights SA's involvement in seed germination, photosynthesis, respiration, growth, flowering, and senescence. SA affects seed germination in a concentration-dependent manner. High concentrations of SA can inhibit germination by inducing oxidative stress, while low concentrations can improve germination under abiotic stress conditions by reducing oxidative damage. SA also interacts with other plant hormones such as abscisic acid (ABA) and gibberellins (GAs) to regulate germination. In terms of photosynthesis, SA can both inhibit and enhance photosynthetic activity depending on its concentration. It affects leaf and chloroplast structure, stomatal closure, chlorophyll content, and enzyme activities like RuBisCO and carbonic anhydrase. SA also provides protection against oxidative stress induced by herbicides and heavy metals. Regarding respiration, SA influences the alternative oxidase (AOX) pathway, which is important for maintaining redox homeostasis and ATP synthesis. It can either stimulate or inhibit respiration depending on its concentration, and it affects mitochondrial function by altering electron transport and oxidative phosphorylation. SA's role in plant growth is complex, with evidence suggesting it can both promote and inhibit growth. Mutant and transgenic plants with altered SA levels exhibit various growth phenotypes, indicating SA's regulatory role in growth processes. SA also interacts with other signaling pathways, such as those involving the mitogen-activated protein kinase (MAPK) cascade, to regulate growth and development. In flowering, SA has been shown to induce flowering in various plant species. It interacts with photoperiod and autonomous pathways, influencing the expression of key flowering genes such as FLC, CO, and SOC1. SA also plays a role in senescence by regulating the expression of senescence-associated genes (SAGs) and interacting with the WRKY53 transcription factor and jasmonic acid (JA) signaling pathway. Overall, SA is a key signaling molecule that integrates multiple physiological processes in plants, contributing to their health, development, and response to environmental challenges.