Jefferson is a census-designated place (CDP) in Jefferson Parish, Louisiana, on the East Bank of the Mississippi River. Jefferson is part of the New Orleans–Metairie–Kenner Metropolitan Statistical Area. The population was 11,843 at the 2000 census. Within Jefferson are also areas known as Old Jefferson and Jefferson Heights.
Jefferson is located at 29°57′51″N 90°9′26″W / 29.96417°N 90.15722°W / 29.96417; -90.15722 (29.964132, -90.157170).
According to the United States Census Bureau, the CDP has a total area of 3.3 square miles (8.5 km²), of which, 2.8 square miles (7.1 km²) of it is land and 0.5 square miles (1.4 km²) of it (16.11%) is water. The western part of Jefferson's Census area was lost to Elmwood during the 2000 Census.