下野国
was a feudal domain under the Tokugawa shogunate of Edo period Japan, located in the Nasu District of Shimotsuke Province (modern-day Tochigi Prefecture), Japan. It was centered on Kurobane "jin'ya" in what is now part of the city of Ōtawara, Tochigi. Kurobane was ruled through all of its history by the "tozama" Ōzeki clan.