(Stenotaphrum secundatum), low, mat-forming perennial grass of the family Poaceae, native to central and southeastern North America and Central America and naturalized along many seacoasts of the world. It is a coarse-textured, vigorous warm-season grass that roots readily along its prostrate stems.

Saint Augustine grass is cultivated as a lawn grass in some areas of Australia and in southern North America. A variety S. s. variegatum, which has white-striped leaves, is grown as an ornamental.