Salt tolerance in plants, including tomato, is influenced by the hyperosmolality-gated calcium-permeable channel (OSCA) gene family, which plays an important role in osmotic stress signaling. In this research, thirteen OSCA gene family members were identified in tomato, which were diversified into four clades, in close association with StOSCA genes (Solanum tuberosum) within clade 3, suggesting conservation among the genus, while five genes also closely clustered with Helianthus annuus, indicating a common ancestral lineage predating species divergence. These genes were unevenly distributed across 8 of 12 tomato chromosomes, with chromosome 2 harboring the highest number of SIOSCA genes (five). The highly conserved RSN_7TM (PF02714) domain was present in all SlOSCA proteins. This domain is known for its role in calcium-permeable ion channels and was further verified by the strict localization of 12 SlOSCA proteins (SlOSCA1-11 and SlOSCA13) in the plasma membrane. Sequence logo analysis validated the conserved amino acid residues, including proline (P), aspartic acid (D), arginine (R), valine (V), glycine (G), and tryptophan (W), from the N-terminal to C-terminal regions. The protein-protein interaction network was centered upon Solyc03g095760.2.1, acting as a major protein interacting with several SlOSCA members, including SlOSCA-1 to SlOSCA-7, except SlOSCA-5. The expression analysis showed higher expression of SlOSCA 2, 8, and 10 across all treatments and tissues, particularly in root tissues, highlighting their role in salinity tolerance. This study thus provides a theoretical basis for targeting the SlOSCA gene family for salt tolerance in tomato, a model plant species, and for translating this approach to other economically important crop species.