Vertical memory devices, and methods of manufacturing the same, include providing a substrate including a cell array region and a peripheral circuit region, forming a mold structure in the cell array region, forming an opening for a common source line passing through the mold structure and extending in a first direction perpendicular to a top surface of the substrate, forming a first contact plug having an inner sidewall delimiting a recessed region in the opening for the common source line, and forming a common source bit line contact electrically connected to the inner sidewall of the first contact plug.