A side protection device fora vehicle according to an embodiment of the present invention may comprise: a main body housing detachably attached to a side of a vehicle; a guard unit rotatably installed in the main body housing, deployed along the full-length direction of the vehicle for protecting the side of the vehicle from an external physical impact; and a fixing unit installed in the main body housing for catching and fixing the main body housing from the side of the vehicle by a manual operation.