In a non-volatile memory device, active fin structures extending in a first direction may be formed on a substrate. A tunnel insulating layer may be formed on surfaces of the active fin structures and bottom surfaces of trenches that may be defined by the active fin structures. A charge trapping layer and a blocking layer may be sequentially formed on the tunnel insulating layer. A gate electrode structure may include first portions disposed over top surfaces of the active fin structures and second portions vertically spaced apart from portions of the charge trapping layer that may be disposed over the bottom surfaces of the trenches, and may extend in a second direction substantially perpendicular to the first direction. Thus, lateral electron diffusion may be reduced in the charge trapping layer, and thereby the data retention performance and/or reliability of the non-volatile memory device may be improved.