The Achirvati (IAST: Aciravati) was an ancient river flowing through what is now Nepal and the northern portion of Uttar Pradesh. It has been identified with the modern Rapti. 
The Achirvati was also known as the Ajiravati or the Airavati. The Chinese pilgrim Yuan Chwang knew it as A-chi-lo. Jain texts mention it as Eravai.
The ancient city of Sravasti, once capital of Kosala Kingdom, stood on the western bank of the Achirvati. It was a tributary of the Sarayu. It was one of the five great rivers that constituted the Ganges group of rivers. It was one of the sacred rivers of the Buddhist midland.