Seasteading is the creation of permanent dwellings in international waters, so-called seasteads, that are independent of established governments. No structure on the high seas has yet been created and recognized as a sovereign state. Proposed structures have included modified cruise ships, refitted oil platforms, and custom-built floating islands.

Some proponents say seasteads can "provide the means for rapid innovation in voluntary governance and reverse environmental damage to our oceans ... and foster entrepreneurship." Some critics fear seasteads may function primarily as a refuge for the wealthy to evade taxes or other national legislation.

While seasteading may guarantee some freedom from unwanted rules, the high seas are regulated internationally through bodies of admiralty law and law of the sea.

The term seasteading is a blend of sea and homesteading, and dates back to the 1960s.

Nomadic ocean life has been practiced for millennia by so-called sea nomad peoples, particularly around Southeast Asia.

Historic inspiration for seasteading includes Venice, which while built on stilts like similar settlements to its North, East or South, is not only a longstanding maritime settlement, but also center of the historic independent state of the Republic of Venice.

Other inspirations include Tenochtitlan, the capital city of the Aztec Empire, founded on an island in Lake Texcoco with connected artificial islands built around it – Mexico City now entirely covers the lake's basin – and floating communities such as the Uru people on Lake Titicaca, the Tanka people in Aberdeen, Hong Kong, and the Makoko in Lagos, Nigeria.

More recent inspirations include: