The Lebanon Valley is part of the much longer Great Valley, a natural lowland route running northeast-southwest and lying just inland from the Blue Ridge Mountains and South Mountain.
The Great Valley, including the Lebanon Valley, has historically been admired for its fertile agricultural land. Beyond the southwestern end of the Lebanon Valley, the Great Valley is known locally as the Cumberland Valley. To the northeast the Great Valley is known locally as the Lehigh Valley. Lebanon Valley College is named for the region. The western part of the valley lies within the Chesapeake Bay watershed. The eastern part lies within the Delaware River watershed.