This article is about a river. There is also a town called Segura in the province of Guipúzcoa, northern Spain.

Segura (Latin Thader, Arabic War-Alabiat, Spanish Segura) is a medium-size river in southeastern Spain.

It starts at Santiago Pontones (province of Jaén), passes Cieza, Murcia, Orihuela, Rojales and ends in the Mediterranean Sea near Guardamar del Segura in the province of Alicante. Some of its tributaries are Mundo, Benamor, Mula and Guadalentín.

Segura river is an irregular river with terrible floods. In 20th century the worst floods were in 1946, 1948, 1973, 1987 and 1989. Its alluvial plain is called the "Vega del Segura" which is a very rich kitchen garden.