Oatgrass is a common name for several plants and may refer to:
Arrhenatherum, oatgrass or button-grass Avenula pubescens, downy oat-grass or downy alpine oatgrass Danthonia californica, California oatgrass plants of the genus Trisetum are known as oatgrass Oats, young plants of which may be referred to as "oat grass"