The Irrawaddy River or Ayeyarwady River, also spelt Ayeyarwaddy is a river that flows from north to south through Burma (Myanmar). It is the country's largest river and most important commercial waterway.

Originating from the confluence of the N'mai and Mali rivers, it flows relatively straight North-South before emptying through the Irrawaddy Delta into the Andaman Sea. Its drainage area of about 255,081 km簡 covers a large part of Burma. After Rudyard Kipling's poem, it is sometimes referred to as 'The Road to Mandalay'.