Saeul is a commune and small town in western Luxembourg, in the canton of Redange. With a population of 983 as of 2023, it is the least populous commune in Luxembourg. As of 2024, the town of Saeul itself, which lies in the south-east of the commune, has a population of 524. In November 2024, it became the last municipality in Luxembourg to reach 1,000 residents.