The Eem is a river in the central Netherlands, located in the province of Utrecht, with a total length of approximately 18 kilometres. It originates in Amersfoort, where the Vallei Canal and several Veluwe creeks converge, most notably the Heiligenberger Beek, the Barneveldse Beek, and the Lunterse Beek. From Amersfoort, the river flows northward through the Eem Valley, passing to the east of Soest, Baarn, and Eemnes before emptying into the Eemmeer near Eemdijk.

The river drains a significant portion of the Gelder Valley and flows through a landscape of polders that are recognized for their scenic value. The surrounding Eem Valley is a relatively flat, agricultural region characteristic of the central Netherlands lowlands.

At roughly 18 kilometres in length, the Eem offers a straightforward linear route from Amersfoort to the Eemmeer, making it a manageable day trip for paddlers. The mouth of the river at Eemdijk opens onto the Eemmeer, which provides the option to extend a journey onto open water.