The Muksu River is a west-flowing river in north-central Gorno-Badakhshan province, Tajikistan. It is a tributary of the Vakhsh River which in turn is a tributary of the Amu Darya. The north side of its valley is the Trans-Alay Range and the south side is formed by the high mountains near the Fedchenko Glacier. It begins at Altyn Mazar at the juncture of the west-flowing Sauksai and the northwest-flowing Seldara rivers. It joins the Kyzyl-Suu (which drains the Alay valley) to form the Surkhob or Vakhsh River. At Altyn Mazar there is a pass leading north to Daroot-Korgan in the Alay Valley.
Coordinates: 39°16′08″N 71°22′48″E / 39.2689°N 71.3799°E / 39.2689; 71.3799