Garyville is a census-designated place (CDP) in St. John the Baptist Parish, Louisiana, United States. The population was 2,775 at the 2000 census. It is part of the New Orleans–Metairie–Kenner Metropolitan Statistical Area. Garyville has the distinction of being the location of the most recent oil refinery built in the United States in 1976 by Marathon Petroleum Company.
Garyville is located at 30°3′26″N 90°37′7″W / 30.05722°N 90.61861°W / 30.05722; -90.61861 (30.057346, -90.618488).
According to the United States Census Bureau, the CDP has a total area of 22.4 square miles (58.0 km²), of which, 20.9 square miles (54.2 km²) of it is land and 1.4 square miles (3.7 km²) of it is water. The total area is 6.43% water.