Petar IV Zrinski (Hungarian: Zrínyi Péter) (6 June 1621 – 30 April 1671) was Ban of Croatia (Viceroy) from 1665 to 1670, general and a writer.

A member of the Zrinski noble family, he was noted for his role in the attempted Croatian-Hungarian Magnate conspiracy to overthrow the Habsburgs, which ultimately led to his execution for high treason.

He was appointed a great captain of Žumberak uskoks, with whom he participated in the Thirty Years' War, in which he distinguished himself during its final phase on the German and Bohemian frontiers.

The conspirators, who hoped to gain foreign aid in their attempts, entered into secret negotiations with a number of nations: including France, Sweden, the Polish-Lithuanian Commonwealth and the Republic of Venice, even the Ottoman Empire.

Their estates were confiscated and their families relocated – Zrinski's wife, Katarina Zrinska, was interned in the Dominican convent in Graz where she fell mentally ill and remained until her death in 1673, two of his daughters died in a monastery, and his son Ivan Antun (John Anthony) died in madness, after twenty years of terrible imprisonment and torture, on 11 November 1703.

Nádasdy, Chief Justice of Hungary, and Styrian governor, Count Hans Erasmus von Tattenbach – were executed (the latter in Graz on 1 December 1671).

Leopold suspended the constitution – already, the Zrinski trial had been conducted by an Austrian, not a Hungarian court – and ruled Hungary like a conquered province.

[7] His final letter addressed to his wife before his execution was titled "Moje drago Zercze" (My dear heart) and had been translated by contemporaries to German, Hungarian, Dutch, French, Italian, English, Latin and Spanish languages from the original Croatian.

He published a translation of his brother's work Adrianskoga mora sirena [hr] (Syren of the Adriatic Sea) in 1660, to which he contributed his own verses and poetic ideas.

[10] Ragusan poet Vladislav Menčetić dedicated his 1665 epic poem Trublja Slovinska to Petar Zrinski, where he was elevated as the saviour of Christendom against the Ottoman Empire.