The Reiu is a long river in southwest Estonia. Its source is Lake Soka in Latvia. It flows generally north. It is a left tributary of the Pärnu River into which it flows near the city of Pärnu. The basin area of Reiu is 917 km² and average discharge 17.3 m³/s.
Reiu is a village in Tahkuranna Parish, Pärnu County in southwestern Estonia. It's located just south of the city of Pärnu (about from the city centre), between Pärnu Bay and Reiu river. As of 2011 Census, the settlement's population was 599.
The village is passed by the National road 4 (part of E67 or the Via Baltica), and is the starting point of the National road 6 ( Valga–Uulu highway).
Reiu is the location of Lottemaa, a theme park inspired by the Lotte from Gadgetville. In Soviet times, the site was home to Kullipesa missile base.
In 2015, a new golf course (Pärnu Bay Golf Links), was opened in Reiu village.
The Raeküla Forest is located in the northern part of the village territory.
On 7 September 2015, Mereküla village was established by detaching the land from Reiu village.