Gahanna, OH has a population of 34,373 and is the 1,228th largest city in the United States. The population density is 2,766 per sq mi which is 974% higher than the Ohio average and 2953% higher than the national average. The median age in Gahanna is 39 which is approximately 1% lower than the Ohio average of 39. In Gahanna, 60% of the population over 15 years of age are married, 94% speak English and 1% speak Spanish. 70% of Gahanna residents were born in Ohio, 23% were born out of state, 1% were born outside of the United States and 6% were foreign born.