Greenbrier is the common name of the plant genus Smilax. It may also refer to:
- Places, United States
- Greenbrier, Arkansas
- Greenbrier, Orange County, Indiana
- Greenbrier, Warrick County, Indiana
- Greenbrier, Tennessee, in Robertson County
- Greenbrier (Great Smoky Mountains), in Sevier County, Tennessee
- Greenbrier County, West Virginia
- Greenbrier River, a river in southeastern West Virginia
- Greenbrier River Trail, a rail trail along the Greenbrier River
- The Greenbrier resort in White Sulphur Springs, West Virginia
- An unincorporated community in Limestone County, Alabama
- Other
- The Greenbrier Companies, an American manufacturer of railroad cars and parts
- Chevrolet Corvair Greenbriar, a van version of the air-cooled Corvair
- Smilax – plant species
- Greenbrier High School in multiple cities