Columbia City is a city in Columbia Township, Whitley County, Indiana, United States. The population was 9,892 at the 2020 Census, up fro…Columbia City is a city in Columbia Township, Whitley County, Indiana, United States. The population was 9,892 at the 2020 Census, up from 8,750 at the 2010 Census, estimated to be 10,064 in 2023. The city is the county seat of Whitley County, and is the largest community therein. It is part of the Fort Wayne MSA.