An OBD connector protective cover includes a clip provided with a pair of openable/closable lugs, a body cover that covers the entire clip including the pair of lugs, a key cylinder provided on a front of the body cover as opening/closing operation means for the pair of lugs and a socket provided on a rear face of the body cover as an opening for inserting a connection terminal section 101 of an OBD connector 100 into the body cover. The pair of lugs are closed through a key operation with the key cylinder, the connection terminal section 101 of the OBD connector 100 and the body cover are integrated together by the lugs holding the connection terminal section 101 of the OBD connector 100, and the body cover constitutes an obstacle to thereby disable access to the connection terminal section 101 from outside.