The Mesopotamian Plain is part of the large Mesopotamia which extends in Iraq and surrounding countries. The plain is almost flat and vast lowland, which has clearly defined physiographic boundaries with the other surrounding physiographic provinces. From the north and east, it is limited by the Low Amplitude Mountainous Province. From the west, the upper part is limited by Al-Jazira Plain, whereas in the lower part by the Western Desert Province. From the south it is limited by the Southern Desert Province. The plain is a huge accumulational geomorphologic unit, where the fluvial, lacustrine, and Aeolian landforms prevail; the fluvial units being the abundant among others. However, estuarine and marine forms also are developed, but restricted to the extreme south-eastern reaches of the plain. Moreover, some erosional landforms are developed in different places, but are not well expressed. In the central eastern part, large alluvial fans are developed with five stages covering vast areas along the Iraqi – Iranian international borders. The geomorphic units are classified according to origin, geomorphic position, and lithology. Some of the significant features are described with some details.
Keywords: Mesopotamian plain, fluvial units, Alluvial fans, Marshes, Aeolian forms.