Probiotics, which are considered as live microbial adjunct conferring health benefits to the host, represent a potentially effective strategy for infectious disease control. Nevertheless, there has been growing concerns about safety, applicability and functionality issues associated with the live probiotic microorganisms. Concurrently, recent observations indicate that even the non-viable counterparts of the probiotic organisms, also known as paraprobiotic, can be used to harness similar beneficial effects. Considering the limitations of probiotic application, paraprobiotics constitute a potential alternative strategy for improving health and wellness of fish and shellfish in aquaculture. Eventhough the concept of paraprobiotic is relatively established in higher vertebrate models and related food production sectors, its application in aquaculture is still in its early stage. In light of this, the present review delineates the concept of paraprobiotic, inactivation methods used for its preparation, the role of paraprobiotic in modifying biological responses as well as their potential application in aquaculture.