A three-dimensional memory device including first and second stacking structures and first and second conductive pillars is provided. The first stacking structure includes first stacking layers stacked along a vertical direction. Each first stacking layer includes a first gate layer, a first channel layer, and a first ferroelectric layer between the first gate and channel layers. The second stacking structure is laterally spaced from the first stacking structure and includes second stacking layers stacked along the vertical direction. Each second stacking layer includes a second gate layer, a second channel layer, and a second ferroelectric layer is between the second gate and channel layers. The first and second gate layers are disposed between the first and second ferroelectric layers, and the first and second conductive pillars extend along the vertical direction in contact respectively with the first and second channel layers.