We report synthesis of phase pure multiferroic YMnO 3 thin films on sapphire (0001) with conducting ZnGaO buffer contact layer. Films were prepared by using pulsed laser deposition technique and characterized using x-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive absorption spectroscopy (EDAX) and magnetic field dependent dielectric measurement techniques. Structural characterizations indicated phase purity and epitaxial nature of the films. The dielectric response indicated an anomaly in dielectric constant ε and tanδ in the vicinity of 30 K, well below the bulk Néel temperature ~ 70 K. This anomaly in ε (T) and tanδ and its magnetic field dependence is explained as an influence of strain due to lattice mismatch between the substrate and YMnO 3 film. A substantial enhancement in magnetocapacitance was also observed for magnetic field applied parallel to ab plane of the film. Our results show that it is possible to tune the multiferroic property of YMnO 3 via changes in ferroelastic route.2