Ivan Tomko Mrnavić (1579–1635 or 1637 or 1639) was a Roman Catholic prelate who served as Bishop of Bosnia (1631–1639)[1][2][3] and an author of historical works.

On 10 November 1631, Ivan Tomko Mrnavić was appointed during the papacy of Pope Urban VIII as Bishop of Bosnia.

His claim was debated by Frang Bardhi in his The Apology of Scanderbeg, published in Venice in 1636.

[4] He claimed that Skanderbeg, the national hero of Albania, was of Slav origin, which prompted Frang Bardhi to write a biography on Skanderbeg published in Venice in 1636[6] as a polemic against him, defending the Albanian identity of Skanderbeg.

[7][8] While bishop, Marnavich was the principal co-consecrator of:[5] His works written in Latin include: His works written in "Illyrian" language include: