Identifying people of exotic origins with isotopes depends upon finding isotopic attributes that are inconsistent with the indigenous population. This task is seldom straightforward and may vary with physical geography, through time, and with cultural practices. Isotopes and trace elements were measured in four Viking Age (8^th to 10^th centuries A.D.) skeletons from Dublin, Ireland, and three from Westness, Orkney. These were compared with other data from these locations and contemporaneous skeletons from Britain. We conclude that the male skeletons from Dublin have disparate origins, two originating beyond the shores of Ireland, and that the female and two male skeletons from Westness are not indigenous to Orkney. However, the homeland of the female, in contrast to the males, is unlikely to be in Scandinavia.