Optimization of cryopreservation media to attenuate oxidative damage on post-thaw spermatozoa is crucial. This study aimed to assess the antioxidant functionality of curcumin-loaded niosomal nanocarriers (CurLNN) on the quality of cryopreserved ram spermatozoa. Semen samples (n=16) of four Dalagh rams were extended with different concentrations (10 or 20 μL) of curcumin (Cur) or CurLNN and then cryopreserved using a standard protocol. The findings indicated that sperm cells exposed to curcumin, specifically CurLNN at a concentration of 20 μL, displayed increased levels of total and progressive motility, greater lateral head displacement and linearity values, improved plasma membrane function, and reduced abnormality (P < 0.05). Viability and plasma membrane functionality increased by supplementing cryopreservation medium with Cur20 and CurLNN (P < 0.05). A significant decline (P < 0.05) in malondialdehyde (MDA) and reactive oxygen species (ROS) concentrations was observed by supplementing cryopreservation medium with both curcumin and its nano-sized. There was a significant (P < 0.05) increase in the percentage of spermatozoa with mitochondrial activity when the cryopreservation medium was incorporated with CurLNN. Spermatozoa treated with CurLNN demonstrated higher viability and lower late apoptosis (P < 0.05) compared with other groups. There were no differences among groups in terms of the percentage of necrotic and early apoptotic spermatozoa. In conclusion, the results of this study demonstrated that nano-sized curcumin, particularly at a 20 µL concentration, had a higher antioxidant potential, leading to improved sperm functional quality by mitigating oxidative damage during cryopreservation.