Ogasawara Nagakuni (??? ??, July 9, 1824 – April 23, 1877) was the 6th and final daimyo of Karatsu Domain in Hizen Province, Kyushu, Japan (modern-day Saga Prefecture).
Before the Meiji Restoration, his courtesy titles were title of Sado no Kami and junior 5th, lower grade court rank (ju go i no ge ????).