The Valdai Hills (Russian: Валда́йская возвы́шенность or Валда́й, Latvian: Valdaja augstiene) are an upland region in the north-west of central Russia running north-south, about midway between Saint Petersburg and Moscow, spanning Leningrad, Novgorod, Tver, Pskov, and Smolensk Oblasts.
The hills are a northward extension of the Central Russian Upland. The ridge is overlain by deposited glacial materials in the form of terminal moraines and other detritus. The Valdai Hills reach their maximum height of 346.9 m (1,138 ft) near Vyshny Volochyok.
The Volga, the Daugava (the Western Dvina), the Lovat, the Msta, the Dnieper, the Syas, and other rivers originate in the Valdai Hills. The region thus is divided between the drainage basins of the Caspian Sea (the Volga), the Black Sea (the Dnieper), and the Baltic Sea (the Msta and the Lovat via the Volkhov, the Syas via Lake Ladoga and the Neva, and the Daugava).