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We report the electronic structures of Ta-doped anatase TiO thin films grown by pulsed laser deposition (PLD) with varying magnetization using a combination of first-principles calculations and near-edge x-ray absorption fine structure (NEXAFS) spectroscopy. The roles of Ta doping and Ti vacancies are clarified, and the observed room-temperature ferromagnetism is attributed to the localized magnetic moments at Ti vacancy sites ferromagnetically ordered by electron charge carriers. O -edge spectra exhibit significant polarization dependence which is discussed and supported by first-principles calculations in relation to both the crystal symmetry and the formation of defects. In particular, anomalous spectral-weight transfer across the entire O edge for the ferromagnetic thin film is associated exclusively with the occurrence of Ti vacancies and strong correlation effects, which result in the enhancement of the direct …