Khopyor (Russian: Хопёр, also transliterated as Khoper) is a river in European Russia, the biggest left tributary of the Don River. Length 979 km, watershed: 61,100 km², mouth width: 300m.Navigable up to 323 km. Maximum discharge is 3720 m³/s, an average discharge is 150 m³/s, a minimum discharge is 45 m³/s.
There are a lot of fishes in the river: bream, zander, roach, rodd, chub, ide, bleak, catfish, pike, perch, asp, burbot.
Towns on the Khopyor River in Orographic sequence are:
Downstream from Borisoglebsk is the Khopyor Nature Preserve, populated with protected beavers, wisents and Russian Desman.
According to legend, an oldman Hopper lived in these places of Penza Oblast . One day he went by steppe and saw 12 springs. The old man took a shovel and assembled all the springs in one big stream. On this stream oldman Hopper built a mill to grind grain for the peasants from nearby villages. Later the river was given the name of its creator.
The river gave its name to the Khoper-Invest company, infamous for its pyramid scheme fraud.