- Jac-Cen-Del MS/HS
- James E Davis School
- Jasper High School
- Jay County Christian Academy
- Jay County High School
- Jefferson High School
- Jeffersonville High School
- Jennings County High School
- Jimtown High School
- John Glenn High School
- Kankakee Valley High School
- Kingdom Academy of Bluffton Inc
- Knightstown High School
- Knox Community High School
- Kokomo High School
- Kouts Middle/High School
- LaCrosse School
- Lake Central High School
- Lakeland Christian Academy
- Lakeland High School
- Lakeview Christian School Inc
- Lakewood Park Christian School
- Lanesville Jr-Sr High School
- Lapel Sr High School
- LaPorte High School
- LaVille Jr-Sr High School
- Lawrence Central High School
- Lawrence North High School
- Lawrenceburg High School
- Lebanon Senior High School
- Leo Junior/Senior High School
- Lewis Cass Jr-Sr High School
- Liberty Christian School
- Lighthouse Christian Academy
- Lincoln High School
- Lincoln Sr High School
- Linton-Stockton High School
- Logansport Community High School
- Loogootee High School
- Lowell Senior High School
- Lutheran High School