Resident Population in Island County, WA was 86.47800 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Island County, WA reached a record high of 87.58100 in January of 2021 and a record low of 27.01100 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Island County, WA - last updated from the United States Federal Reserve on April of 2026.