Advanced combustion processes in compression ignition CI engines have been developed as a result of the increasing demand for more efficient and clean energy conversion devices. This study uses experimental data to examine how hydrogen enrichment and the inclusion of nanoparticles affect the performance metrics of a single-cylinder direct injection diesel engine. Hydrogen was injected through the intake manifold at a constant flow rate of H₂ (2 L/min), and metal oxide nanoparticles were combined with the fuel at concentrations of 50 ppm and 100 ppm. Under different load conditions, the experiment was carried out at a constant speed of 1500 rpm. It was found that using H₂ (2 L/min) + 100 ppm nanoparticles raised the brake thermal efficiency from 30% for diesel to 33%. Consequently, there was a 10% rise. Similarly, from 11.8 MJ/kWh to 10.6 MJ/kWh, the brake specific energy consumption dropped. According to emission study, smoke opacity dropped from 28% to 18%, CO emissions dropped from 0.23% to 0.16%, and HC emissions dropped from 42 ppm to 32 ppm. However, because of the high combustion temperature, NOx emissions also rose from 680 parts per million for diesel fuel to 820 parts per million for hydrogen-enriched nano-fuel blends. According to the results of the combustion analysis, the maximum heat release rate increases from 45 J/°CA to 82 J/°CA for hydrogen-enriched nano-fuel blends, while the peak cylinder pressure climbs from 68 bar, which corresponds to diesel fuel, to 90 bar. The findings demonstrate that adding nanoparticles along with hydrogen enrichment improves engine performance, combustion efficiency, and emission characteristics, making it a viable strategy for running cleaner CI engines.