Reduction in the occurrence and severity of disease in aquaculture would improve the productivity, profitability, efficiency and welfare of aquacultural fish. Genetic approaches that have been successfully implemented in aquaculture to enhance disease resistance and reduce disease incidence include classical selection, genetic marker‐assisted selection, intraspecific crossbreeding, interspecific hybridization and transgenesis. The rate and speed of improvement in disease resistance varies from one genetic enhancement programme to another. Genome editing with zinc finger nucleases (ZFNs), transcription activator‐like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPRs)‐CRISPR‐associated protein 9 (Cas9) opens avenues for targeted genome modifications. This technology can be applied in aquaculture to manipulate disease‐resistance genes by means of gene knock‐in, gene knockout and regulation of gene expression. The maximum rate of improvement can be achieved by combining different genetic enhancement programmes. Here, we present a review for the current and future prospect of disease reduction in aquaculture with genetic and genomic technologies.