The purpose of this study is to utilize the formation water produced in Egyptian oil and gas wells as a feedstock for electrolysis to produce hydrogen gas. In this study, hydrogen is produced via electrolysis of such highly-saline waste liquid (formation water) which is eventually produced together with oil/gas. It also, emphasizes the benefits of employing the electrolysis technique (as eco-friendly technique, which uses electrons as clean reagents, with zero-CO2 emission) while producing high purity hydrogen gas and outlines the valorisation of wasted formation water, to be a potential source of hydrogen. Lastly, the article outlines the procedures used for producing hydrogen using electrolysis of various electrolytes, for the purpose of comparison, i.e., acidic, alkaline, and neutral media using two types of electrodes' materials, i.e., graphite rods and aluminium sheets as the cathodes and the anodes during the electrolysis process. Current-potential relations are recorded with an aim to check the method's efficiency levels. The research concludes that a power saving of more than 75% could be achieved for hydrogen gas production using formation water compared to the case of using acidic electrolyte. Moreover, the exploration of hydrogen production from different formation water samples demonstrated the versatility and potential of these sources, especially when mixed, offering promising possibilities for sustainable electrolysis. These results have profound implications for advancing sustainable energy production and offer valuable contributions to the ongoing efforts towards decarbonisation and environmental sustainability. This opens up the opportunities and potential benefits of green hydrogen production in Egypt