Ada, AlabamaAda is an unincorporated community in Montgomery County, Alabama, United States. Ada is located at the intersection of U.S. Route 331 and Alabama State Route 94, south of Montgomery.HistoryA post office operated under the name Ada from 1881 to 1922. Ada was the name of the first postmaster's wife.DemographicsAccording to the census returns from 1850 [United States census|1850]–2010 for Alabama, it has never reported a population figure separately on the U.S. Census.