John Ernest IV was Duke of Saxe-Saalfeld from 1680 to 1729 and the founder of the House of Saxe-Coburg-Saalfeld.
- Occupation
- aristocrat, politician
- Citizenship
- Saxe-Coburg-Saalfeld
- Born
- August 22, 1658
- Died
- February 17, 1729, December 19, 1729, December 17, 1729