A foldable mechanism and a display device including the foldable mechanism are disclosed. The foldable mechanism includes a first folding hinge, a second folding hinge, a third folding hinge, a fourth folding hinge, a first casing, a second casing, a third casing, and a fourth casing. The foldable mechanism is multifunctional and has both inward bending and outward bending functions, so that the display device can operate in three display states: a tablet display state, a mobile phone display state, and a notebook display state.