Baron János Jeszenák de Királyfia (Slovak: Ján Jesenák; 22 January 1800 – 10 October 1849) was a Hungarian politician, noble, Inspector of the Lutheran Diocese of Cisdanubia.

Baron János (IV) Jeszenák was born into an old noble family in Pozsony (today: Bratislava, Slovakia) on 22 January 1800.

As a member of the Hungarian delegation, he participated in the coronation ceremony of George IV on 19 July 1821 led by ambassador, later Minister besides the King Paul III Anton, Prince Esterházy.

He supported, among others, Széchenyi's idea about construction of a bridge between Buda and Pest, proposal of Orders about new buildings of the Hungarian National Museum and also embraced the cause of the "Védegylet" defence society.

[3] As a reliable reformer, he was appointed Lord Lieutenant (Count; comes) then Government Commissioner of Nyitra County by Minister of the Interior Bertalan Szemere.