Structural and wettability properties of titanium nitride (TiN) thin films for different annealing temperatures have been characterized, and critical parameters have been identified. TiN thin films were deposited onto the silicon substrates by using the magneto-sputtering technique for two different powers, 150 W and 350 W. Subsequently, the films were annealed in the air at 573–973 K for the duration of 1 h. The X-ray diffraction spectra showed the appearance of titanium dioxide (TiO2) above 773 K temperature (termed as transformation temperature). The relative intensity of the TiO2 peaks rapidly increase with the temperature. The thin and dense oxide overlayer appeared at 773 K, and the thicker oxide layer was observed at 973 K. Surface roughness is observed to increase with the increase in annealing temperature but with the limiting value at 773 K; after that, the roughness decreases because of the stable formation of TiO2. Similarly, with an increase in temperature, the hydrophobic nature of thin films becomes more significant; however at 973 K, the formation of TiO2 declines the hydrophobic nature, and thus the surface energy increases. Transformation temperature is also found to be responsible for the reduction in grain size and compressive strain of the thin film.