The Syamzhena (Russian: Сямжена) is a river in Sokolsky and Syamzhensky Districts of Vologda Oblast in Russia.

The center of Syamzhensky District, the selo of Syamzha, is located on both banks of the Syamzhena.

The names of Syamzhensky District and its center, the selo of Syamzha (which was established in 1935 by merging a number of villages at the crossing of the Syamzhena by the highway connecting Vologda and Arkhangelsk) are derived from the Syamzhena.

The source of the Syamzhena is located in the northeast of Sokolsky District.

[3] In Sokolsky District, the Syamzhena flows west, further it turns north and enters Syamzhensky District, and at the confluence of the Shichenga from the right the river turns west again.