This study aims to establish a novel foundational framework for designing pultruded glass fiber-reinforced polymer (pGFRP) columns using the Direct Strength Method (DSM). The approach incorporates: (i) the influence of initial geometric imperfections (GI) and (ii) the interaction between material crushing and elastic buckling, for global buckling (GB) failure. In this paper, only global flexural (FB) and flexural-torsional (FTB) buckling failures are considered, including potential interactions with crushing. The proposed methodology builds upon the single-curve approach adopted in steel design codes and applied in the DSM framework. A rigorous selection process identified 124 experimental tests of axially compressed pGFRP columns from the literature. Using this data, a simplified design approach is developed through an optimization problem solved using an evolutionary algorithm. The proposed design methodology is compared with the ASCE 74–23 and CEN/TS 19101:2022 standards, offering insights and suggestions for improving the current design procedures. The findings from this study aim to drive the development of a unified DSM-based design approach capable of: (i) accommodating different material characterization standards for predicting crushing phenomena, (ii) addressing local-global-crushing interactions, (iii) incorporating GIs, and (iv) accounting for the post-buckling strength reserve associated with local buckling modes. Future research will focus on reliability-based design, computational simulations, and parametric studies to extend the applicability of the DSM proposal to structural scenarios beyond the scope of current experimental tests.