Lower Burma (Burmese: အောက်မြန်မာပြည်, also called Outer Myanmar) is a geographic region of Burma (Myanmar) and includes the low-lying Irrawaddy delta (Ayeyarwady, Bago and Yangon Regions), as well as coastal regions of the country (Rakhine and Mon States and Tanintharyi Region).
In the Burmese language, people originating from Upper Burma are typically called a-nya tha (အညာသား), whereas those from Lower Burma are called auk tha (အောက်သား).
Historically, Lower Burma referred to the part of Burma annexed by the British Empire after the end of the Second Anglo-Burmese War in 1852, plus the former kingdom of Arakan and the territory of Tenasserim which the British had taken control of in 1826. Lower Burma was centred at Rangoon, and composed of all of the coast of modern Burma, and also the lower basin of the Irrawaddy River, including Prome. Until the early 19th century, Lower Burma was predominantly populated by the Mon and Karen tribes and was a historical stronghold of the Mon people.