Elmira / ˌ ɛ l ˈ m aɪ r ə / is the largest city and the county seat of Chemung County, New York, United States.It is the principal city of the Elmira, New York, metropolitan statistical area, which encompasses Chemung County.The population was 29,200 at the 2010 census.The population shrank by slightly more than 7 percent to a population of 27,110 by 2020.