As the United Kingdom careens wildly towards Brexit on October 31, 2019, there is much speculation about what this means for European Union and UK fisheries. What’s most important from a marine governance perspective is that Brexit almost guarantees fisheries conflict in some form. A worst-case scenario could see armed conflict occur between EU countries and the UK that may draw in other Northeast Atlantic countries including Norway, Iceland, and the Faroe Islands. A best-case conflict scenario is a trade war that could financially ruin seafood companies in the UK and Europe. More fundamentally, Brexit undermines the entire Common Fisheries Policy, with uncertain implications in the long and short term.