Schoenoplectus subterminalis is a species of flowering plant in the sedge family known by the common names water bulrush, water club-rush, and swaying bulrush.

It is native to North America, where it is known from many parts of the Canada and the United States.

It is a perennial herb forming mats or tufts of very narrow cylindrical stems easily exceeding one meter long.

When the plant grows in water only the inflorescences and the tips of the leaf blades break the surface.

The inflorescence is generally a single cone-shaped spikelet at the end of the stem accompanied by a stiff, stemlike bract.