The Oka–Don Lowlands (Russian: Окско-Донская равнина) (also: Oka–Don Plain), is a flat plain in European Russia, bounded on the north by the Oka River (and the Meshchera Lowlands), on the south by the Don River, on the west by the Central Russian Upland, and on the east by the Volga Upland.

The terrain is flat, with altitude averaging 160 meters above sea level, and the rivers meander on broad floodplains.

Agricultural use of the plain is high, mostly for grain growing – wheat, barley and rye.

The primary grains are wheat, barley and rye, with 'industrial' crops such as sunflower seeds, sugar beets, and potatoes.

Before modern development, the plain was forb meadow-steppe, with forest groves of pine, oak, and black alder along the river banks.