Significance We know more about the settlement of Polynesia than we do about the settlement of the Mariana Islands in the western Pacific. There is debate over where people came from to get to the Marianas, with various lines of evidence pointing to the Philippines, Indonesia, New Guinea, or the Bismarck Archipelago, and over how the ancestors of the present Mariana Islanders, the Chamorro, might be related to Polynesians. We analyzed ancient DNA from Guam from two skeletons dating to ∼2,200 y ago and found that their ancestry is linked to the Philippines. Moreover, they are closely related to early Lapita skeletons from Vanuatu and Tonga, suggesting that the early Mariana Islanders may have been involved in the colonization of Polynesia.