Resident Population in Ellis County, OK was 3.64800 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Ellis County, OK reached a record high of 6.41000 in January of 1982 and a record low of 3.64800 in January of 2023. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Ellis County, OK - last updated from the United States Federal Reserve on May of 2024.