This micro-credential course is the first of six short courses introducing laymen to common diseases in aquaculture. The aquaculture industry has been a booming trade of late due to food security issues and threats to natural fisheries. However, as aquaculture businesses thrive, the occurrence of diseases in these confined farms, tanks, and ponds increases too. Therefore, basic knowledge of the types of diseases that target aquaculture species would greatly help in understanding and then preventing the disease from spreading and causing financial losses. In this series of MCs, we will cover the common diseases that plague marine and freshwater aquaculture systems in Malaysia and neighbouring Asian countries, as well as the basic management, medication, and mitigation strategies for these diseases.