Niwa Nagahiro
 Viscount Niwa Nagahiro (丹羽長裕) (April 17 1859 – July 29 1886) was a Japanese daimyo of the early Meiji period who ruled Nihonmatsu han. The 9th son of Yonezawa lord Uesugi Narinori he succeeded to the Nihonmatsu headship in 1868. Nihonmatsu had just lost in the Boshin War and as one of the conditions for its surrender to the Imperial Japanese Army Niwa Nagakuni the previous daimyo retired.