<p>In the present study, a Co-Cr-Mo-based alloy coating was deposited on AISI 4140 steel substrates using laser cladding deposition (LCD) to investigate the influence of laser power on microstructural evolution, phase formation, and mechanical response. Coatings were produced at three laser power levels (2500 W, 2900 W, and 3400 W), with all other processing parameters held constant. The feedstock powder was characterized in terms of morphology and particle size distribution prior to deposition. The cladded layers were examined by light optical microscopy (LOM), scanning electron microscopy (SEM) coupled with energy-dispersive spectroscopy (EDS), x-ray diffraction (XRD), and microhardness testing, while transmission electron microscopy (TEM) was employed to further elucidate nanoscale phase constituents and interfacial features. The results revealed that increasing laser power leads to thicker coatings and a slight enlargement of the heat-affected zone (HAZ), without introducing macroscopic defects. The coating microstructure consisted predominantly of a Co-based solid solution with dendritic morphology, which progressively coarsened with increasing heat input. The application of higher laser power promoted interdendritic Mo segregation, microporosity, and the formation of Co₃Mo intermetallic phases, as confirmed by XRD and SEM/EDS analyses. Hardness measurements showed the highest coating hardness at the lowest laser power, due to refined microstructures. In contrast, pronounced hardness peaks were observed at the coating–substrate interface, particularly at high laser power, associated with transformed microstructures in the heat-affected zone.</p>