Fly ash produced due to burning of coal in thermal power plants for generation of energy is a significant industrial solid waste material. There are many research works carried out for eco-utilization of fly ash in various ways. This study is focused on originating, chemical composition, chemical properties, and catalytic activity of coal fly ash for production of biodiesel. The raw fly ash (RFA) after recycling can be used as a suitable solid catalyst because of various benefits as compared with other homogenous catalysts. The presence of aluminosilicate and some rare earth metals in coal burning fly ash considered it as a suitable candidate material for various catalytic, adsorption, and other extraction processes including fuel production. However, the existence of hazardous materials is a significant environmental problem, which must be resolved in order to avoid water, air, and soil contamination. Only 1-2% conversion of biodiesel was achieved from soybean oil by using RFA. The acid-treated fly ash (ATFA) was mixed with a metal hydroxide like KOH or NaOH and Ca(OH) ₂ and was then calcined at a temperature of 700°C for about 3 hours to formulate the solid catalyst. This solid catalyst synthesized by the combination of NaOH with ATFA is labelled as SC-Na, which exhibits better performance compared to those obtained only by simple mixing ATFA with Ca (OH) ₂ or NaOH and the optimum mass ratio of NaOH with ATFA was 3:1, which achieves 97.8% of biodiesel conversion. Most of the applied modified processes are hydrothermal, thermal treatment, and alkali activation, which enhances the structural, textural, and morphological properties. The form of active catalyst could be achieved by either ion exchange or impregnation technology. There are many catalytic systems based on fly ash used for production of biodiesel, but among these, the fly ash/CaO and zeolite derived fly ash method is more sustainable and beneficial.