Nonvolatile memory device

The nonvolatile memory device may include a substrate including a first region and a second region. A string line group may be disposed on the substrate in the first region, and a bias interconnection group may be disposed above the substrate in the second region. The bias interconnection group may include a string select bias interconnection, cell bias interconnections, and a ground select bias interconnection, which may be respectively electrically connected to a string select line, word lines, and a ground select line of the string line group. The string select bias interconnection may be disposed between the ground select bias interconnection and the cell bias interconnections of the bias interconnection group.