Transition metal catalysts supported on natural materials offer promising avenues for sustainable organic synthesis. In this study, we present the synthesis, characterisation, and catalytic performance of copper nanoparticles supported on montmorillonite K10 (CuMK10) as a heterogeneous catalyst for hydroamination reactions. CuMK10, synthesised through a robust and established nanoparticle synthesis methodology, demonstrates remarkable catalytic efficiency and selectivity in the synthesis of imines via hydroamination of terminal alkynes. The catalyst exhibits exceptional regioselectivity, predominantly yielding Markovnikov products, demonstrating its potential as a versatile tool in organic synthesis. Moreover, CuMK10 shows favourable reusability, offering economic benefits and practical utility due to its ease of recovery and reuse. Comprehensive structural and mechanistic studies provide insights into the catalyst's performance, paving the way for the development of efficient and environmentally benign catalytic systems.