<p>The enhanced formability of TRIP-aided steels relies on the transformation of retained austenite to martensite in microstructure (TRIP effect) at the deformation stage. However, a TRIP effect which has been completed prematurely or has not been sufficiently activated during deformation can adversely affect formability. Therefore, an austenite–martensite transformation that occurs progressively during deformation is essential for optimizing the formability of TRIP-aided steels. This study introduces a novel approach to enhancing the formability of TRIP-aided steels by taking advantage of the temperature dependency of retained austenite stability. The study aims to improve the formability by initially restricting the austenite–martensite transformation in the steel and exploiting the TRIP effect later during the deformation process. For this purpose, a two-stage deformation process was designed. In the first stage (1), the steel was deformed at elevated temperatures (50 °C, 100 °C, and 150 °C) to three predetermined strain levels (5%, 10%, and 15%), effectively suppressing the austenite-to-martensite transformation. In the second stage (2), the steel was cooled to room temperature (RT) to reactivate the TRIP effect and then deformed until fracture. The purpose of the two-stage deformation process was to use the additional strain hardening effect (through TRIP transformation) at the second stage for further delaying the fracture and thereby improving the formability. The results show significant improvement in total elongation: 6.6% (50°C), 9.9% (100°C), 32.2% (150°C) at 15% pre-warm deformation (PWD) and minimal strength compromise: Only 5.2% reduction in tensile strength at optimal conditions (15% PWD, 150°C).</p>