Károly Hieronymi (1 October 1836 – 4 May 1911) was a Hungarian engineer and politician, who served as Interior Minister between 1892 and 1895.
He was a supporter of former Prime Minister Kálmán Tisza.
As Minister of Trade he modernized the train services, for the Hungarian State Railways he nationalized the Budapest-Pécs, the Duna-Dráva and the Zagreb-Karlovac railway lines.
He insured the independence of the railway goods turnover aiming at the seaports and its tranquillity.