Mount Ida is a city in and county seat of Montgomery County, Arkansas, United States. Founded in 1842, the city saw a silver boom in the 1880s bring early prosperity and economic development to the area.

Montgomery County is a county in the U.S. state of Arkansas. As of the 2020 census, the population was 8,484. The county seat is Mount Ida. Montgomery County is Arkansas's 45th county, formed on December 9, 1842, and named after Richard Montgomery, an American Revolutionary War general.