The Klyazma (, Klyaz'ma or Kliazma), a river in the Moscow, Nizhny Novgorod, Ivanovo and Vladimir Oblasts in Russia, and a left tributary of the Oka.
The long river's drainage basin is . The Klyazma usually freezes up in November and stays under the ice until mid-April, although in faster-moving stretches ice-free water occurs until the air temperature drops below .
The largest tributaries of the Klyazma include (from source to mouth):
The Klyazma is navigable within from its estuary and in the area of the Klyazminskoye Reservoir. The cities of Gorokhovets, Mendeleyevo, Pavlovsky Posad, Vladimir, Kovrov, Shchyolkovo, Losino-Petrovsky, Noginsk, Orekhovo-Zuyevo, Sobinka and Vyazniki stand on the shores of the Klyazma River.
The basin of the Klyazma formed the center of the Vladimir-Suzdal principality in the 12th to 14th centuries CE.