County Laois is a county in Ireland. It is part of the Eastern and Midland Region and in the province of Leinster. It was known as Queen's County from 1556 to 1922. The modern county takes its name from Loígis, a medieval kingdom. Historically, it has also been known as County Leix. At the 2022 census, the population of the county was 91,657, an increase of 56% since the 2002 census.