Salix sessilifolia is a species of willow known by the common name northwest sandbar willow. It is native to the west coast of North America from British Columbia to northern California, where it grows on sandy and gravelly riverbanks, floodplains, and sandbars. It is a shrub growing 3 to 5 meters in height, sometimes forming colonial thickets of clones by sprouting repeatedly from its root system. The leaves are up to 12 centimeters long, oval with pointed tips, edged with spiny teeth, and generally coated thinly in silky hairs. The inflorescence is a catkin of flowers, male catkins up to 4.5 centimeters long and female catkins longer and more slender.