Plants have evolutionarily developed multiple and complex defense mechanisms against abiotic stresses. Among these, the Terpene Synthase (TPS) gene family plays a pivotal role in the biosynthesis of terpenoids—key secondary metabolites involved in plant defense regulation and stress responses. Despite its significance, genomic characterization of this gene family in extremophile plant species, such as Stylosanthes scabra, remains absent from the literature. Thus, this study aimed to structurally characterize TPS genes in S. scabra and evaluate their root transcriptome expression profiles under 24-h water deprivation. A total of 42 TPS sequences with conserved domains were identified in the S. scabra reference genome. Phylogenetic analysis revealed five distinct subfamilies, with TPS-a and TPS-b being the most abundant. Regarding motif analysis, the catalytic DDxxD motif was conserved across all TPS subfamilies except TPS-c. In the root tissue of S. scabra, 12 TPS genes were found to be involved in the plant’s response to 24-h water deprivation, with five showing downregulation and seven maintaining constitutive expression. This transcriptional response suggests a potential association with gibberellin signaling suppression as part of the plant’s adaptive strategy to drought stress. Our findings enhance the understanding of TPS genes associated with the S. scabra genome, suggesting their potential role in the plant’s high tolerance to water deficit. Additionally, this study provides a foundation for future research in plant biotechnology aimed at improving drought resilience.