Meridian is the eighth most populous city in the U.S. state of Mississippi, with a population of 35,052 at the 2020 census. It is the county seat o…Meridian is the eighth most populous city in the U.S. state of Mississippi, with a population of 35,052 at the 2020 census. It is the county seat of Lauderdale County and the principal city of the Meridian, Mississippi Micropolitan Statistical Area. Along major highways, the city is 93 mi east of Jackson; 154 mi southwest of Birmingham, Alabama; 202 mi northeast of New Orleans, Louisiana; and 231 mi southeast of Memphis, Tennessee.