<p>Chloroprene rubber/natural rubber (CR/NR) nanocomposites were prepared using a two-roll mill by incorporating a hybrid filler of octavinyl-polyhedral oligomeric silsesquioxane (OV-POSS) and carboxylated carbon nanotubes (COOH-CNTs). This study explored how varying filler content influenced the composites’ curing, mechanical, swelling, abrasion, and compression properties. Increasing the filler content raised torque values and cure rate index, while scorch time and optimum cure time decreased, indicating faster vulcanization. Tensile strength and modulus at 100% elongation improved up to 4 phr, showing a 29.6% and 58% increase, respectively, over the unfilled rubber. Hardness and tear strength also increased, whereas elongation at break and rebound resilience declined. Compression set rose with filler content, suggesting reduced elasticity. Swelling and abrasion resistance improved significantly at 4 phr but declined at higher levels due to agglomeration and poor dispersion. Overall, 4 phr of hybrid filler was found to be the optimal loading for enhanced composite performance.</p> Graphical Abstract <p></p>