Biodiversity mainstreaming, the consideration of biodiversity across fisheries and the range of actions taken by both fisheries and conservation governance streams is the subject of this paper. Evidence is presented that the global fishery community incrementally adopted sustainable development principles from both before and after the 1992 adoption of the Convention on Biological Diversity, integrating a broader set of ecosystems goals into fisheries. Actions taken by the Food and Agriculture Organization of the United Nations (FAO) and regional and national fishery agencies to fulfil their mandate are discussed, in addition to objectives for more sustainable fisheries that have led to significant expansions in legal frameworks, policies and practices in terms of biodiversity conservation. The paper also highlights the growing importance of cross-sectoral cooperation in the resolution of historical disagreements between fisheries and environmental interests, in spite of the various sectoral interests. In this evolution, despite many target stocks not yet being sustainably managed, fisheries approaches are progressively focusing on a broader range of biodiversity considerations, whereas conservation interests are increasingly adopting more socially inclusive approaches. Looking ahead to the future, biodiversity conservation will continue to be of growing importance in fisheries, and presented here, are examples of how past and on-going developments in fisheries challenge the pessimistic picture promoted by some environment-focused advocacy papers. To continue this successful mainstreaming, greater implementation efforts are needed to deliver outcomes at all scales, requiring greater capacity, particularly in developing countries and strengthening of investment in integrated partnerships between fisheries and environment sectors.