Martensitic medium‐Mn steels have attracted significant attention for their excellent ultimate tensile strength, high ductility, and low austenitizing temperatures but remain susceptible to hydrogen embrittlement (HE). In this study, we investigated the role of ε carbides formed during paint baking in mitigating HE in martensitic medium‐Mn steels. Paint baking at 180 °C for 20 min reduced the diffusible H content absorbed during austenitizing from ∼0.12 to 0.04 mass ppm. Subsequent room-temperature aging nearly eliminated diffusible H, resulting in H‐free specimens. The as-austenitized specimen underwent premature failure during tensile deformation due to diffusible H absorbed during austenitizing, whereas the H-free austenitized specimen exhibited a typical tensile flow curve without premature failure. Comparisons between H-free austenitized and paint-baked specimens revealed that paint baking increased yield strength through ɛ carbide formation and enhanced ductility by stabilizing retained austenite, delaying its transformation into martensite. Under identical H-charging conditions, the paint-baked specimens exhibited lower diffusible H content and higher non-diffusible H content, significantly improving HE resistance. Thermal desorption analysis revealed that H atoms trapped within ε carbides were released at 300–420 °C during their decomposition into cementite. Thus, the activation energy for peak 2 (225.2 kJ/mol) does not represent the activation energy for H desorption from ε carbides or retained austenite but rather the activation energy for the formation of cementite from ε carbides.