A memory device includes a memory cell array, a row address decoder configured to generate a plurality of main word line driving signals and a plurality of sub word line driving signals, based on an odd signal representing that a main word line driving signal driving an odd word line is activated, generate a plurality of encoded sub word line driving signals used for driving a target word line by outputting the plurality of sub word line driving signals in a first order, and, based on an even signal representing that a main word line driving signal driving an even word line is activated, generate the plurality of encoded sub word line driving signals by outputting the plurality of sub word line driving signals in a second order, and a word line driving circuit configured to drive the target word line at a first voltage level or a second voltage level.