The present invention discloses a locking device and an electronic device. The locking device is configured to lock a first part and a second part which are mutually assembled in the electronic device, and comprises a stop gear and a locking mechanism; the stop gear includes a first spacing part located on the first part and a second spacing part located on the second part, and the first spacing part and the second spacing part are mutually acted to allow the first part and the second part to generate relative displacement in a special direction; and the locking mechanism includes an overturn cover plate hinged to the first part and a second withstanding part located at the second part, the overturn cover plate is provided with a first withstanding part, the overturn cover plate is rotated, and the first withstanding part and the second withstanding part can mutually withstand to restrict the relative displacement of the first part and the second part in the special direction. The locking device and electronic device realize the appearance effect of notebook computer housing without visual screws through cooperation of a stop gear and a locking mechanism, and is simple and reliable in structure and easy to dismount and maintain.