The Halmahera Sea languages, also known as the Raja Ampat-South Halmahera languages, are a branch of Malayo-Polynesian languages spoken on islands in the Halmahera Sea, and on its margins from the south-eastern coast of Halmahera to the Raja Ampat Islands of the western tip of New Guinea.The languages of the Raja Ampat Islands show a strong Papuan substratum influence; it is not clear that they are actually Austronesian as opposed to relexified Papuan languages.Remijsen (2001) and Blust (1978) linked the languages of Raja Ampat to the South Halmahera languages.