All Steel manufacturing industry generates by-products today, and one such by-product is Energy Optimized Furnace slag, i.e, EOF, steel slag. But EOF steel slag is less used in cement manufacturing. This study examines the feasibility of using EOF steel slag to replace natural aggregates in concrete, with the intention of minimizing waste disposal and conserving natural resources. Standardized tests were conducted to evaluate the physical, chemical, and mechanical characteristics of EOF steel slag. The results thus obtained were compared with those of natural aggregates. Concrete mix proportions were formulated in this research to obtain M30 grade concrete. The natural coarse aggregate in the designed mix was replaced with EOF steel slag aggregate at different percentages, from 0% to 100% in steps of 10%. Experimental studies were carried out to analyze the properties of fresh and hardened concrete, such as workability, compressive strength, splitting tensile strength, and flexural strength, for various replacement percentages of EOF steel slag aggregate. The best replacement ratio was found considering the outcomes of fresh and hardened concrete characteristics. Moreover, the correlation between flexural strength, splitting tensile strength, and compressive strength was investigated. The mechanical characteristics of EOF steel slag aggregates are similar to those of natural coarse aggregates. Nevertheless, the greater water absorption and surface roughness of EOF slag affect the workability of concrete. The mechanical characteristics of concrete made using a full replacement of natural aggregate with EOF steel slag are quite similar to those of normal concrete. From this study, one learns that concrete made from 100% replacement of EOF Steel slag as coarse aggregate has better strength characteristics. By utilizing EOF steel slag as a substitute for natural coarse aggregate in concrete, the issue of unsafe, environment-degrading practice of dumping steel slag can be avoided. In addition, an industrial byproduct like steel slag is utilized in an eco-friendly way. Use of EOF steel slag in concrete is an eco-friendly, useful, and cost-saving step. Use of EOF steel slag in concrete is an eco-friendly, useful, and cost-saving step.