A gear assembly including a driving gear and a driven gear and an electronic device are provided. The driving gear includes a pawl pivoted on a first surface and an elastic member disposed in a slot of the driving gear. The driven gear includes a ratchet disposed on a second surface facing the first surface. When the driving gear rotates with a driving speed along a driving direction, a centrifugal force is generated to drive the pawl moving to a clutching position to be engaged with the ratchet and drives the driven gear rotating with the driving gear. When the driving gear rotates with a nominal speed slower than the driving speed along a direction opposite to the driving direction, the engagement between the pawl and the ratchet is released, and the pawl is back to a nominal position so the driven gear does not rotate with the driving gear.