Auburn is a city in Lee County, Alabama, United States. It is the largest city in eastern Alabama, with a 2020 population of 76,143. It is a principal city of the Auburn-Opelika Metropolitan Area. The Auburn-Opelika, AL MSA with a population of 158,991, along with the Columbus, GA-AL MSA and Tuskegee, Alabama, comprises the greater Columbus-Auburn-Opelika, GA-AL CSA, a region home to 501,649 residents.