Agrostis hallii is a species of grass known by the common name Hall's bentgrass. It is native to the west coast of the United States from far southern Washington to central California, where it grows in the woodlands and forests of the coastal mountain ranges. This is a rhizomatous perennial grass growing up to about a meter tall. It has flat leaves up to 20 centimeters long and thin or dense inflorescences of spikelets.