The South-Pacific Claims Treaty was a 1799 treaty between Great Britain and Louisiana laying out a set of rules for colonization in the south Pacific. It was signed following the claim of western Australia as the colony of New Louisiana by Louisiana in 1798 by Robert Lachance. The colony's borders were in direct contest with British claims on Australia, and this treaty resolved the conflict and set out rules to avoid future issues in regards to colonization. Among them are the following:
- It set out clearly defined borders between New Louisiana and New South Wales.
- Louisiana and Britain can colonize anywhere they please as long as their borders are not in direct contact.
- Colonies of each nation in close proximity must be open to trade.
- Military ships are not allowed in colonial waters of the other nation.
- Neither nation has the power to settle on any lands claimed by the other power for any reason, even a civilian one.