Suzaka Domain (須坂藩 Suzaka-han) was a feudal domain under the Tokugawa shogunate of Edo period Japan. It is located in Shinano Province, Honshū. The domain was centered at Suzaka Jin’ya, located in what is now part of the town of Suzaka in Nagano Prefecture.
Suzaka Domain was established for Hori Naoshige, the 4th son of Hori Naomasa, daimyō of Sanjō Domain in Echigo Province. Naoshige had holdings of 2,000 koku in Shimōsa Province and 6,000 koku in Suzaka, which had been awarded for his services during the Battle of Sekigahara. To this, he added 4,000 koku for services during the Siege of Osaka, which elevated him to daimyō status. His son, Hori Naomasu, gave the 2000 koku in Shimōsa to his younger brothers, reducing the domain to 10,000 koku. The Hori clan continued to rule Suzaka uninterrupted until the Meiji restoration.
The Hori clan served in a number of administrative posts within the government of the Tokugawa shogunate. The 9th daimyō, Hori Naoteru, opened a han school. The 12th daimyō, Hori Naotake, reformed the domain’s finances and encouraged the develop of ginseng cultivation as a cash crop.
During the Bakumatsu period, the 13th daimyō, Hori Naotora, reformed the domain’s military, introducing western-style firearms. He also served as a wakadoshiyori within the administration of the Tokugawa shogunate. he committed seppuku in Edo Castle in protest over the policies of Shogun Tokugawa Yoshinobu. During the Boshin War, the domain quickly supported the imperial side, and participated in the Battle of Utsunomiya Castle, Battle of Kōshū-Katsunuma, Battle of Hokuetsu and Battle of Aizu. In July 1871, with the abolition of the han system, Suzaka Domain briefly became Suzaka Prefecture, and was merged into the newly created Nagano Prefecture. Under the new Meiji government, Hori Naoakira, the last daimyo of Suzaka Domain was given the kazoku peerage title of shishaku (viscount).