Marrero is a census-designated place (CDP) in Jefferson Parish, Louisiana, United States. Marrero is on the West Bank of the Mississippi River, within the New Orleans–Metairie–Kenner Metropolitan Statistical Area. The population was 36,165 at the 2000 census.
Marrero is located at 29°53′10″N 90°6′36″W / 29.88611°N 90.11°W / 29.88611; -90.11 (29.886017, -90.109930).
According to the United States Census Bureau, the CDP has a total area of 8.6 square miles (22.2 km²), of which, 8.1 square miles (20.8 km²) of it is land and 0.5 square miles (1.3 km²) of it (5.96%) is water..