Civil construction is one of the most environmentally impactful industries, accounting for approximately 5% of global carbon dioxide (CO2) emissions, primarily due to the cement production process. To mitigate this impact, it is essential to diversify the materials used in the sector, as the demand for cement is unlikely to decrease significantly. Incorporating vegetable fibers into the cementitious matrix offers a sustainable solution to replace synthetic fibers, addressing the inherent low tensile strength of cement-based materials. These fibers act as reinforcement by controlling crack propagation. Jute fibers were selected for this study due to their promising properties, including tensile strength, and Young's modulus, with average values of 250 MPa and 30 GPa, respectively. The research focuses on developing mortars reinforced with jute fibers, using a matrix composed of 50% cement, 20% fly ash, and 30% metakaolin. The addition of pozzolanic materials to the matrix aims to partially replace cement, improving the mortar's durability and reducing deleterious chemical reactions within the matrix. For this study, mortars with varying fiber percentages and lengths were tested and evaluated through physical and mechanical characterization. Compared to the reference sample, the fiber-reinforced mortars exhibited increased water absorption and void index due to higher porosity introduced by the fibers. Despite the increase in matrix porosity and the reduction in compressive strength compared to the reference, the fiber-reinforced mortars demonstrated an average improvement of more than 50% in the flexural strength of the composite. Regarding toughness, the reinforced composites presented an average toughness around 16.7 times greater than that of the reference sample. This indicates a significant capacity to absorb and dissipate energy during impacts or shocks. These results highlight the potential of cementitious composites reinforced with jute fibers as a promising and sustainable alternative for the construction sector, particularly for use in masonry coatings.