The Most Reverend John Janssen | |
|---|---|
| Bishop of Belleville | |
 | |
| Church | Roman Catholic Church |
| See | Diocese of Belleville |
| In office | April 25, 1888—July 2, 1913 |
| Successor | Henry J. Althoff |
| Orders | |
| Ordination | November 19, 1858 by Henry Damian Juncker |
| Consecration | April 25, 1888 by Patrick Feehan |
| Personal details | |
| Born | March 3, 1835 |
| Died | July 2, 1913 (aged 78) Belleville, Illinois, USA |
John Janssen (March 3, 1835 – July 2, 1913) was a German-born prelate of the Roman Catholic Church. He served as the first bishop of the new Diocese of Belleville in Illinois from 1888 until his death in 1913.