| János Jacobinus | |
| Nationality: | Hungarian |
| Order: | Chancellor of Transylvania |
| Term Start: | April 1603 |
| Term End: | 17 July 1603 |
| Predecessor: | Vacant |
| Successor: | Mihály Káthay |
| Birth Date: | 1574 |
| Birth Place: | Kolozsvár, Principality of Transylvania (today: Cluj-Napoca, Romania) |
| Death Date: | 17 July 1603 |
| Death Place: | Brassó, Principality of Transylvania (today: Brașov, Romania) |
János Jacobinus (1574 – 17 July 1603)[1] was a Hungarian politician and historian of Saxon origin in the Principality of Transylvania, who served as Chancellor of Transylvania for a short time in 1603.
He was the son of Bernát Jacobinus, a prestigious citizen of Kolozsvár (today: Cluj-Napoca, Romania). After finishing studies, he became notary of his birthplace between 1592 and 1598. He participated in the Wallachian Campaign of 1595 against Sinan Pasha. He described the events in detail and reliability. He served as secretary for Princes Sigismund Báthory, Andrew Báthory and Michael the Brave since May 1598.
In September 1600, he defected from Michael to the insurgent nobles. He became the secretary of the Transylvanian Chancellery after Sigismund Báthory retake his throne. In this capacity, he, probably, controlled the domestic policy of Transylvania around that time, when the position of Chancellor remained vacant. He joined to Mózes Székely in April 1603 who appointed him as Chancellor. Several months later, he died in the battle of Brassó (today: Brașov, Romania) along with his lord against Radu Şerban, ruler of Wallachia.
For a short time, he was the owner of the Wolphard–Kakas House, an important Renaissance monument on the Main square of Kolozsvár. General István Csáky gave him the house for his services. However the original owner, István Kakas, a diplomat and traveler sued back that from Jacobinus.