Jidayu Koizumi (小泉次大夫, 1539 - 1624 January 27) was the Secretary of Water and Hatamoto magistrate of the early Edo period.

Jidayu Koizumi
Statue of Jidayu Koizumi
LordImagawa Ujizane (until 1615)
Tokugawa Ieyasu (after 1615)
Born1539 (1539)
DiedJanuary 27, 1624(1624-01-27) (aged 84–85)
Era name and dates
Shogunate: Tokugawa
ClansUematsu → Koizumi (renamed)