We report on the room temperature ferromagnetism and CH4 gas sensing of titanium oxynitride prepared by milling and annealing at 1100 degrees C in a nitrogen gas environment. Structural analyses revealed a metastable orthorhombic TiO2 phase after milling for 120 h. The 120 h milled TiO2 particles and subsequently annealed in nitrogen gas at 1100 degrees C showed the formation of titanium oxynitride (TiOxNy) with a tetragonal crystal structure. An FCC metastable TiOxNy phase was also observed with a lattice parameter a = 4.235 angstrom. The vibrating sample magnetometer and electron paramagnetic analyses showed that the milled and TiOxNy samples possess room temperature ferromagnetism. Gas sensing measurements were carried out toward CH4 and H-2 gases. The TiOxNy nanostructures demonstrated higher sensing response and selectivity to CH4 gas at room temperature. The enhanced response of 1010 and sensitivity of 50.12 ppm(-1) at a concentration of 20 ppm CH4 are associated with higher surface area, pore diameter and surface defects such as oxygen vacancies and Ti3+, as evidenced from the Brunauer-Emmet Teller, photoluminescence, electron paramagnetic resonance and x-ray photoelectron analyses. (C) 2017 Elsevier B.V. All rights reserved.