The increasing deployment of shared transmission corridors for High-Voltage Alternating Current (HVAC) and High-Voltage Direct Current (HVDC) systems has intensified the need to evaluate electromagnetic compatibility in hybrid overhead line configurations. This study presents an analytical methodology to estimate the electric field magnitude and magnetic flux density generated by hybrid HVAC–HVDC transmission lines under steady-state operating conditions. The electric field is determined using the Maxwell potential matrix combined with the image method, while the magnetic field is obtained from a formulation based on the Biot–Savart law. Two representative case studies were analyzed with identical electrical operating conditions but different transverse conductor arrangements to evaluate the influence of geometry on the electromagnetic environment of the corridor. The results show that variations in the spatial configuration of the conductors produce noticeable changes in the location and magnitude of the electric and magnetic field maxima across the right-of-way. These findings demonstrate that conductor geometry plays a key role in the electromagnetic behavior of hybrid corridors and should be considered in the design and assessment of HVAC–HVDC transmission systems.