A high-fidelity lift-off process using bilayer ultraviolet nanoimprint lithography (UV-NIL) to fabricate nanosized metal pattern was demonstrated. High O-2 reactive ion etching (RIE) selectivity of the imprinted resist pattern to the underlayer is necessary to create the undercut pattern profile that is essential for the stable lift-off process. A methacryloxypropyl-terminated polydimethylsiloxane (M-PDMS)-based UV-curable liquid-phase imprint resin and a polyvinyl alcohol (PVA) underlayer were applied to bilayer UV-NIL for the high-fidelity lift-off process. The M-PDMS-based imprinted resist pattern showed high etch resistance to O-2 plasma and the undercut pattern profile of the PVA underlayer for the lift-off process was formed by the O-2 RIE process. The size and shape of the imprinted resist patterns were hardly changed during PVA underlayer etching by O-2 RIE. As a result, high-fidelity and high-aspect-ratio metal patterns without rabbit-ear-shaped defects were fabricated by the lift-off process using bilayer UV-NIL with the M-PDMS-based imprint resin, which has high etch resistance to O-2 RIE, and the PVA underlayer.