This work investigates the application of the Taguchi method to optimize the printing parameters for Fused Deposition Modelling (FDM) in order to improve the elongation of Polylactic Acid (PLA) square lattice structure. FDM, a widely used additive manufacturing (AM) technique, is known for its flexibility, versatility, and efficiency in creating intricate structures. Our focus was on lattice structures made of PLA, a sustainable material offering robustness and lightness, ideal for various industrial applications. The research aimed to optimize parameters such as printing temperature, printing speed, and layer height to improve the elongation at break, a crucial property determining the material’s flexibility and durability. Using the Taguchi method, an efficient statistical approach, we systematically analyzed the impact of these parameters on elongation. The study was conducted using an FDM printer and involved meticulous experimental design based on the L9 OA (orthogonal array). The outcomes were evaluated using signal-to-noise (S/N) ratios and analysis of variance (ANOVA), revealing that printing speed significantly influenced elongation, followed by layer height and printing temperature. The best combination, which produced the maximum elongation, was found to be 0.3 mm layer height, 190 °C printing temperature, and 100 mm/s printing speed. The study’s conclusions are essential for sectors that depend on FDM to produce robust, lightweight components, especially those that need custom or precision-driven manufacturing. So, lattice-structure integrated components can utilized in various sectors, including medical, avionics, and automotive.