As the abstract of this article claims,
Madagascar was one of the last landmasses to be reached by people ... Madagascar was settled approximately 1200 years ago by a very small group of women (approx. 30), most of Indonesian descent (approx. 93%).
So is Madagascar the most-recently settled landmass in the world?
(I do not know what a good definition of "settle" is, but I might suggest this: Multiple generations living and reproducing continuously. This is to exclude places like Antarctica.)