大草原（英语：Prairie）指地球上干旱（半干旱）地区较少长树的一望无际的平坦草原地带，如北美大草原和蒙古高原大草原等。

世界草原定义：Pampas、Prairie、Savanna、Steppe和Veld。Pampas专指南美无树木的潘帕斯大草原；Prairie专指较少长树的北美大草原和蒙古高原大草原；Savanna专指非洲热带（亚热带）的稀树大草原（比如苏丹草原）和美国东南部的无树平原；Steppe专指从东欧横穿前苏联南部直至西伯利亚的大片地区上的无树干草原（比如东欧大草原）；Veld专指南部非洲高地上的稀树草原。

Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type. Temperate grassland regions include the Pampas of Argentina, Brazil and Uruguay as well as the steppes of Eurasia. Lands typically referred to as "prairie" tend to be in North America. The term encompasses the area referred to as the Interior Lowlands of Canada, the United States, and Mexico, which includes all of the Great Plains as well as the wetter, somewhat hillier land to the east. In the U.S., the area is constituted by most or all of the states of North Dakota, South Dakota, Nebraska, Kansas, and Oklahoma, and sizable parts of the states of Montana, Wyoming, Colorado, New Mexico, Texas, Missouri, Iowa, Illinois, Ohio, Indiana, Wisconsin, and western and southern Minnesota. The Central Valley of California is also a prairie. The Canadian Prairies occupy vast areas of Manitoba, Saskatchewan, and Alberta.