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 recently built oil refinery in the United States; it was established in 1976 by Marathon Petroleum Company.
Garyville is located at 30°3′26″N 90°37′7″W (30.057346, -90.618488).
According to the United States Census Bureau, the CDP has a total area of 22.4 square miles (58 km2), of which 20.9 square miles (54 km2) is land and 1.4 square miles (3.6 km2) is water.
As of the census of 2000, there were 2,775 people, 913 households, and 717 families residing in the CDP. The population density was 132.6 people per square mile (51.2/km2). There were 984 housing units at an average density of 47.0 per square mile (18.2/km2). The racial makeup of the CDP was 46.49% White, 52.43% African American, 0.14% Native American, 0.14% Asian, 0.07% Pacific Islander, 0.04% from other races, and 0.68% from two or more races. Hispanic or Latino of any race were 0.72% of the population.