A nonvolatile memory device according to an embodiment includes a substrate having an upper surface, and a gate structure disposed over the substrate. The gate structure includes at least one gate electrode layer pattern and at least one gate insulation layer pattern, which are alternately stacked along a first direction perpendicular to the upper surface. The gate structure extends in a second direction perpendicular to the first direction. The nonvolatile memory device includes a ferroelectric layer disposed on at least a portion of one sidewall surface of the gate structure. The one sidewall surface of the gate structure forms a plane substantially parallel to the first and second directions. The nonvolatile memory device includes a channel layer disposed on the ferroelectric layer, and a source electrode structure and a drain electrode structure disposed to contact the channel layer and spaced apart from each other in the second direction.