This study proposes a space-efficient microstrip antenna capable of dual polarization, specifically engineered for Vehicle-to-Everything (V2X) systems in the 5.9 GHz range. With physical dimensions normalized to approximately 0.2λ × 0.2λ × 0.03λ, the design is suitable for integration into space-constrained vehicular platforms. Dual linear polarizations are realized by exciting two orthogonal fundamental modes within a single radiating element. Simulation data indicates the antenna covers the 5.86–5.96 GHz band (100 MHz bandwidth) with an impedance match of better than −10 dB. Notably, the port isolation exceeds 36 dB. A stable radiation performance is obtained with a peak realized gain of approximately 5.2 dBi for both polarizations. Owing to its compact size, dual-polarization capability, high port isolation, and satisfactory radiation characteristics, this antenna is highly suitable for V2X integration.