Abstract: The efficient recycling of vanadium from converter vanadium-bearing slag is highly significant for sustainable development and circular economy. The key to developing novel processes and improving traditional routes lies in the thermodynamic data. In this study, the equilibrium phase relations for the Fe₂O₃–TiO₂–V₂O₅ system at 1200°C in air were investigated using a high-temperature equilibrium-quenching technique, followed by analysis using scanning electron microscopy-energy dispersive X-ray spectrometer and X-ray photoelectron spectroscopy. One liquid-phase region, two two-phase regions (liquid–rutile and liquid–ferropseudobrookite), and one three-phase region (liquid–rutile–ferropseudobrookite) were determined. The variation in the TiO₂ and V₂O₅ contents with the Fe₂O₃ content was examined for rutile and ferropseudobrookite solid solutions. However, on further comparison with the predictions of FactSage 8.1, significant discrepancies were identified, highlighting that greater attention must be paid to updating the current thermodynamic database related to vanadium-bearing slag systems.