A flexible electronic device including a first flexible substrate, an electronic component, and a control device is provided. The electronic component includes a conductive layer. The control device includes at least one integrated circuit and a circuit layer set. The circuit layer set includes a plurality of circuit layers and at least one first dielectric layer, and at least a portion of the first dielectric layer is interposed between two adjacent circuit layers. The integrated circuit is electrically connected to the electronic component through the circuit layer set and the conductive layer. At least a portion of the conductive layer and at least a portion of one circuit layer are integrally formed, and the conductive layer and the circuit layer are both disposed on the first flexible substrate. A fabricating method of a flexible electronic device is also provided.