A common building material, concrete may fracture when subjected to mechanical loads and environmental pressure. These cracks can compromise its structural integrity and allow moisture to penetrate, which might cause the reinforcing steel to rust. Recent advancements in self-healing concrete investigated the application of microorganisms that can autonomously generate calcium carbonate (CaCO3) for crack repair. This research determined an innovative approach to enriching concrete's strength and environmental sustainability by incorporating the coconut fibre (CF) and Bacillus subtilis bacteria. A 10% bacterial solution with a concentration of 107 CFU/ml, along with waste CF, was added to concrete mixtures in varying amounts (0, 1, 2, 3, 4, and 5%) to evaluate its effectiveness as a micro-reinforcement additive for crack control and mechanical performance enhancement. The prepared concrete specimens underwent curing, and their mechanical properties were evaluated at 7, 14, and 28 days. The blend that performed the best was subjected to microstructural examination. The concrete containing 1% CF showed better mechanical characteristics after 28 days of curing, with values of 46.66 MPa for compressive strength (CS), 6.88 MPa for splitting tensile strength (STS), and 9.33 MPa for flexural strength (FS). This mix's microstructural examination revealed calcium carbonate (CaCO₃) formation, confirming effective crack healing and enhanced durability. This method utilizes agricultural waste as a reinforcing material, promoting sustainable practices in construction and enhancing the durability and service life of concrete structures.