Janusz Radziwiłł is the name of several Polish–Lithuanian nobles:
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Janusz Radziwiłł (1579–1620)
Janusz Radziwiłł ( lt, Jonušas Radvila; 2 July 1579 – 3 December 1620) was a noble and magnate of the Polish–Lithuanian Commonwealth. He was the deputy cup-bearer of the Grand Duchy of Lithuania since 1599, the castellan of Vilnius sinc ...
, castellan of Vilnius and the starost of Borysów
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Janusz Radziwiłł (1612–55), signatory of the Union of Kėdainiai
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Janusz Radziwiłł (1880–1967), conservative politician in the Second Polish Republic
{{hndis, name=Radziwiłł, Janusz