Applying genomics in fisheries represents a transformative approach to understanding and managing aquatic resources. Genomic technologies, including high-throughput sequencing and bioinformatics, provide comprehensive insights into the genetic makeup of fish populations. This enables the identification of genetic diversity, population structure, and adaptive traits, which are crucial for effective conservation and sustainable management. Genomics aids in the detection of overfishing, habitat loss, and environmental changes by monitoring genetic variation and health across populations. Additionally, it enhances selective breeding programs in aquaculture by identifying markers for desirable traits, such as disease resistance and growth rates, leading to improved stock quality and productivity. Furthermore, genomic data support the management of wild fish stocks by informing the design of marine protected areas and guiding restocking efforts. Overall, integrating genomics into fisheries science fosters a more precise and informed approach to preserving aquatic biodiversity and ensuring the long-term sustainability of fishery resources. This chapter highlights the fundamentals of genomics and its application in fisheries and aquaculture. The discussions in this chapter will provide insights into various procedures involved in genomic analysis and a brief idea of how bioinformatics can be used to interpret genomic data.