The alphamegalog of the cities of Alabama lists the largest city in Alabama for each letter of the alphabet. In this case, ‘largest’ is based on population within the city proper.

Auburn
Birmingham
Center Point
Dothan
Enterprise
Florence
Gadsden
Huntsville
Irondale
Jasper
Kimberly
Leeds
Montgomery
Northport
Opelika
Prattville
(no Q)
Russellville
Selma
Tuscaloosa
Union Springs
Vestavia Hills
Wetumpka
(no X)
York
(no Z)