| Type: | Bishop |
| Honorific Prefix: | The Most Reverend |
| Johannes Knijff | |
| Bishop of Groningen | |
| Education: | University of Leuven |
| Consecration: | 5 December 1563 |
| Consecrated By: | Antoine Perrenot de Granvelle |
| Appointed: | 8 August 1561 |
| Enthroned: | 3 October 1568 |
| Death Date: | 7 October 1576 |
| Death Place: | Groningen |
| Predecessor: | Diocese established |
| Successor: | Jan van Bruhesen |
| Honorific Suffix: | O.F.M. |
| Term End: | 7 October 1576 |
Johannes Knijff, O.F.M. (also Johann Knijff or Joannes Knijff Ius, Utrecht,? – Groningen, 7 October 1576)[1] was the first bishop of the Diocese of Groningen.
He was a Franciscan who had studied at Leuven. In 1561, he was appointed bishop of the newly established diocese of Groningen. He was consecrated bishop by Cardinal Granvelle in Brussels on 5 December 1563. Groningen resisted the arrival of a bishop. It was not until 1568 that Knijff, supported by Alva's troops, could take his diocese in the cathedral. In 1576, he died of the plague. Due to the fear of infection, the deceased bishop was buried quickly and without much ceremony in a free grave in the ambulatory east of the altar. Later, his remains were exhumed and placed in a crypt under the choir. Not a stone or a grave monument has been preserved.
Although a successor was appointed after his death, Knijff was, in fact, the only bishop who exercised the office in Groningen until the re-establishment of the diocese in 1956.