Recently, a non-local yet possibly UV-complete quantum field theory has been constructed by deforming a two-dimensional CFT by the composite operator JT, where J is a chiral U(1) current and T is a component of the stress tensor. Assuming the original CFT was a holographic CFT, we work out the holographic dual of its JT deformation. We find that the dual spacetime is still AdS(3), but with modified boundary conditions that mix the metric and the Chern-Simons gauge field dual to the U(1) current. We show that when the coefficient of the chiral anomaly for J vanishes, the energy and thermodynamics of black holes obeying these modified boundary conditions precisely reproduce the previously derived field theory spectrum and thermodynamics. Our ...