Freedom is one of the most enduring conceptual frameworks for thinking about the oceans and their use. Popularized by Grotius in the 17th century, the doctrine of “freedom of the seas” remains to the present day powerful both as a rhetorical device and as a guide for policy. But the degree to which freedom of the seas has eroded in recent decades has often been overlooked. Several of the key elements of that doctrine have either collapsed or are under great strain. A confluence of economic, scientific, strategic, and environmental factors is producing a paradigm shift regarding the oceans.