The Treaty of Perth, signed 2 July 1266, ended military conflict between Magnus the Lawmender of Norway and Alexander III of Scotland over possession of the Hebrides and the Isle of Man.

The Hebrides and the Isle of Man had become Norwegian territory during centuries when both Scotland and Norway were still forming themselves as coherent nation-states, and Norwegian control had been formalised in 1098, when Edgar of Scotland signed the islands over to Magnus III of Norway.

Håkon had planned to renew military action the following summer, but he died in Orkney during the winter.

His successor, King Magnus the Lawmender, sued for peace and the Treaty was agreed after negotiations in Perth during 1265 and 1266.

[3] In the treaty, Scotland confirmed Norwegian sovereignty over Shetland and Orkney and Norway recognised Scottish sovereignty over the disputed territories in return for a lump sum of 4,000 marks and an annuity of 100 marks.