In this study, we describe the synthesis of an efficient catalyst for the acylation of alcohols, phenols, and amines in the presence of 3,3′-(ethane-1,2-diyl)bis(1-methyl-1H-imidazol-3-ium) tetrachloroferrate [DIL]2+[2FeCl4]2− and acetyl chloride (acylating reagent). Remarkably, when exposed to 7 mol% of catalyst [DIL]2+[2FeCl4]2− in a solvent-free environment, acetyl chloride demonstrated excellent acylation activity in a shorter period of time. As a result, a generic approach for the acylation of alcohols, phenols, and amines has been developed. As an ionic liquid, [DIL]2+[2FeCl4]2− can be easily recovered and reused up to five times in a row with little loss of catalytic activity. TGA and DSC analyses were also performed to determine the thermal robustness of [DIL]2+[2FeCl4]2−. We were able to illustrate the several advantages of this acylation approach. It provides better yields in less time and opens up the possibility of a safe, environmentally friendly remedy for acylation reaction.