Stipan/Stjepan Konzul Istranin, or Stephanus Consul (1521 — after 1568), was a 16th-century Croatian Protestant reformator who authored and translated religious books to Čakavian dialect.

At that time Buzet belonged to the Habsburg monarchy and was under the jurisdiction of the Roman Catholic Diocese of Koper, which used the Old Slavonic language for liturgical texts.

[3][full citation needed] Istranin began his career in Stari Pazin as parish priest who wrote Glagolitic texts until 1549 when he was banished for being Protestant.

[1] Based on the advice of Primož Trubar Istranin went to Ljubljana in 1559 where Antun Dalmatin was already engaged to translate liturgical books.

[5] The South Slavic Bible Institute was established in Urach in January 1561 by Hans von Ungnad who was its owner and patron.