马扎鲁尼河是圭亚那的河流，位于该国北部，由库尤尼-马扎鲁尼区负责管辖，属于埃塞奎博河的一部分，河道全长560公里，发源自帕卡赖马山脉。

The Mazaruni River is a tributary of the Essequibo River in northern Guyana. Its source is in the remote western forests of the Pakaraima Mountains and its confluence with the Cuyuni River is near Bartica. As it descends from the Guiana Highlands the river runs south-east, past Issano, then northward to Bartica. The river is a source of alluvial gold.