Pressure overload-induced cardiac hypertrophy occurs in response to chronic blood pressure increase, and dysfunction of Ca1.2 calcium channel involves in cardiac hypertrophic processes by perturbing intracellular calcium concentration ([Ca]) and calcium-dependent signaling. As a carbohydrate-binding protein, galectin-1 (Gal-1) is found to bind with Ca1.2 channel, which regulates vascular Ca1.2 channel functions and blood pressure. However, the potential roles of Gal-1 in cardiac Ca1.2 channel (Ca1.2) and cardiomyocyte hypertrophy remain elusive. By whole-cell patch clamp, we find Gal-1 decreases the I with or without isoproterenol (ISO) application by reducing the channel membrane expression in neonatal rat ventricular myocytes (NRVMs). Moreover, Gal-1 could inhibit the current densities of Ca1.2 by an alternative exon 9*-dependent manner in heterologously expressed HEK293 cells. Of significance, overexpression of Gal-1 diminishes ISO or KCl-induced [Ca] elevation and attenuates ISO-induced hypertrophy in NRVMs. Mechanistically, Gal-1 decreases the ISO or Bay K8644-induced phosphorylation of intracellular calcium-dependent signaling proteins δCaMKII and HDAC4, and inhibits ISO-triggered translocation of HDAC4 in NRVMs. Pathologically, we observe that the expressions of Gal-1 and Ca1.2 channels are synchronously increased in rat hypertrophic cardiomyocytes and hearts. Taken together, our study indicates that Gal-1 reduces the channel membrane expression to inhibit the currents of Ca1.2 in a splice-variant specific manner, which diminishes [Ca] elevation, and attenuates cardiomyocyte hypertrophy by inhibiting the phosphorylation of δCaMKII and HDAC4. Furthermore, our work suggests that dysregulated Gal-1 and Ca1.2 alternative exon 9* might be attributed to the pathological processes of cardiac hypertrophy, and provides a potential anti-hypertrophic target in the heart.