Prince Radziwill Hieronim Mikolaj
- Category : 1885-births
- Type : MGP
- Profile : 1/4 - Investigating / Opportunist
- Definition : Split - Small (10,25,34)
- Incarnation Cross : RAX Penetration 4
Polish aristocrat, landlord in Balice, and great-grandson of Prince Maciej Radziwiłł.
He married Archduchess Renata of Austria on 16 January 1909 in Żywiec. They had six children. He and his children carried the style of Serene Highness.
He was deported to a NKVD Gulag during the Soviet occupation of Poland and died on 6 April 1945.