An optical disk drive (ODD) including a shell and a locking module is provided. The shell includes a main body portion and a side portion, and the side portion is connected to the main body portion. A concave space is formed between a side surface of the main body portion and a top surface of the side portion. The locking module is disposed inside the concave space. The ODD is detachably held in a support frame of an electronic device through the locking module. In addition, a locking module is also provided.