[2] Johnson County is included in the Indianapolis-Carmel-Anderson, IN Metropolitan Statistical Area.

It was named for John Johnson, a Justice of the Indiana Supreme Court.

[4] This is probably John Johnson of Knox County, delegate to the State constitutional convention, appointed to the Supreme Court in 1816.

The south end of the county is also home to the Camp Atterbury military installation.

The commissioners are charged with executing the acts legislated by the council, collecting revenue, and managing the day-to-day functions of the county government.

The judges on each of the courts is elected to a term of four years and must be a member of the Indiana Bar Association.

These include sheriff, coroner, assessor, auditor, recorder, surveyor, and circuit court clerk Each of these elected officers serves terms of four years and oversee different parts of the county government.

[12] As of the 2010 United States Census, there were 139,654 people, 52,242 households, and 37,711 families residing in the county.