Carmel is a suburban city in Hamilton County, Indiana, United States, immediately north of Indianapolis. With a population of 103,606 as of …Carmel is a suburban city in Hamilton County, Indiana, United States, immediately north of Indianapolis. With a population of 103,606 as of the 2024 census, the city spans 49 square miles across Clay Township and is bordered by the White River to the east and the Boone County line to the west. Carmel was home to one of the first electronic automated traffic signals in the country, and constructed 155 roundabouts between 1997 and 2025.