Prince Krzysztof Radziwiłł (Lithuanian: Kristupas Radvila) (22 March 1585, Biržai – 19 November 1640) was a Polish–Lithuanian noble (szlachcic), and a notable magnate, politician and military commander of his epoch.

He took part in the campaign against the Swedes in the Baltic region in 1621–1622 (Polish-Swedish War), where he agreed to a controversial truce (as he had no permission to negotiate it from the king or the Sejm).

He was an opponent of Catholic king Sigismund III Vasa, but a supporter of his more tolerant son, Władysław IV.

On his lands in Kėdainiai he founded a major Calvinist cultural and religious centre,[2] which flourished till the 19th century as a center of the Lithuanian Reformed Church.

Radziwiłł collected various curiosities at the Lubcha Castle: minerals, mollusc shells, corals, hunting trophies, whale bones, elephant tusk, nut shells, and similar items.