Hammond is the largest city in Tangipahoa Parish, Louisiana, United States, located 45 miles east of Baton Rouge and 45 miles northwest of New Orleans. Its population was 20,019 in the 2010 U.S. census, and 21,359 at the 2020 population estimates program. Hammond is home to Southeastern Louisiana University. It is the principal city of the Hammond metropolitan statistical area, which includes all of Tangipahoa Parish and is a part of the Baton Rouge-Hammond combined statistical area.