A district of Japan is dissolved when all towns or villages in the district become cities or are merged into the city. The following is a list of dissolved districts of Japan. The date shown is the day the district was dissolved (i.e. the district was active until that date) and the reason why the district was dissolved is also shown.
Before Edo period Unknown Suruga District (駿河郡), Suruga, Tokaido (Renamed to Suntō District) Unknown Kudara District (百済郡), Settsu, (Merged into either Higashinari and Sumiyoshi Districts) Unknown Nuttari District (沼垂郡), Echigo, Hokurikudo (Merged into Kanbara District) Unknown Tajihi District (百済郡), Kawachi, (Split into Tanboku, Tannan and Yakami Districts) Sengoku Era Hinai District (比内郡), Mutsu, Tozando (Merged into Akita District in Dewa Province) Sengoku Era Ogashima District (小鹿島郡), Dewa, Tozando (Merged into Akita District) Sengoku Era Yamada District (山田郡), Owari, Tokaido (Split and merged into Kasugai and Aichi Districts) Early Edo Period Hanawa (鼻和郡), Hiraka (平賀郡), and Inaka (田舎郡) Districts, Mutsu, Tozando (Merged to form Tsugaru District) Early Edo Period Hiyama District (檜山郡), Dewa, Tozando (Renamed to Yamamoto District) Early Edo Period Toshima District (豊島郡), Dewa, Tozando (Renamed to Kawabe District) Early Edo Period Yamamoto District (山本郡), Dewa, Tozando (Renamed to Senboku District) Early Edo Period Yuza District (遊佐郡), Dewa, Tozando (Renamed to Akumi District) Early Edo Period Kujibiki District (櫛引郡), Dewa, Tozando (Merged into Tagawa District) Edo Period Shikama District (色麻郡), Mutsu, Tozando (Merged into Kami District) 1634 Nukanobe District (糠部郡), Mutsu, Tozando (Split into Kita, Sannohe, Ninohe, and Kunohe Districts) 1700 Noto District (能登郡), Noto, Hokurikudo (Renamed to Kashima District) 1700 Kaga District (加賀郡), Kaga, Hokurikudo (Renamed to Kahoku District) Edo Period Mashiki District (益城郡), Higo, Saikaido (Split into Kamimashiki and Shimomashiki Districts)
1868 to 1895 Tōhoku 1878 Kita District (北郡), Mutsu (Split into Kamikita and Shimokita Districts in Aomori Prefecture) 1878 Tsugaru District (津軽郡), Mutsu (Split into Kitatsugaru, Minamitsugaru, Higashitsugaru, Nishitsugaru and Nakatsugaru Districts in Aomori Prefecture) 1878 Hei District (閉伊郡), Rikuchū (Split into Kitahei, Minamihei, Higashihei, Nishihei and Nakahei Districts in Iwate Prefecture) 1878 Iwai District (磐井郡), Rikuchū (Split into Higashiiwai and Nishiiwai Districts in Iwate Prefecture) 1878 Kunohe District (九戸郡), Rikuchū (Split into Kitakunohe and Minamikunohe Districts in Iwate Prefecture) 1878 Waga District (和賀郡), Rikuchū (Split into Higashiwaga and Nishiwaga Districts in Iwate Prefecture) 1878 Akita District (秋田郡), Ugo (Split into Kitaakita and Minamiakita Districts in Akita Prefecture) 1878 Tagawa District (田川郡), Uzen (Split into Higashitagawa and Nishitagawa Districts in Yamagata Prefecture) 1878 Murayama District (村山郡), Uzen (Split into Kitamurayama, Minamimurayama, Higashimurayama, and Nishimurayama Districts in Yamagata Prefecture) 1878 Okitama District (置賜郡), Uzen (Split into Higashiokitama, Nishiokitama, and Minamiokitama Districts in Yamagata Prefecture) 1878 Aizu District (会津郡), Iwashiro (Split into Kitaaizu and Minamiaizu Districts in Fukushima Prefecture) 1878 Shirakawa District (白川郡), Iwaki (Renamed to Higashishirakawa District in Fukushima Prefecture) 1878 Shirakawa District (白河郡), Iwaki (Renamed to Nishishirakawa District in Fukushima Prefecture) Kantō 1878 Ibaraki District (茨城郡), Hitachi (Split into Higashiibaraki and Nishiibaraki Districts in Ibaraki Prefecture) 1878 Tsuga District (都賀郡), Shimotsuke (Split into Kamitsuga and Shimotsuga Districts in Tochigi Prefecture) 1878 Gunma District (群馬郡), Kōzuke (Split into Higashigunma and Nishigunma Districts in Gunma Prefecture) 1878 Kanra District (甘楽郡), Kōzuke (Split into Kitakanra and Minamikanra Districts in Gunma Prefecture) 1878 Seta District (勢多郡), Kōzuke (Split into Kitaseta and Minamiseta Districts in Gunma Prefecture) 1878 Habu District (埴生郡), Kazusa (Renamed to Kamihabu District in Chiba Prefecture) 1878 Habu District (埴生郡), Shimōsa (Renamed to Shimohabu District in Chiba Prefecture) 1878 Sōma District (相馬郡), Shimōsa (Split into Kitasōma District in Ibaraki Prefecture and Minamisōma District in Chiba Prefecture) 1878 Katsushika District (葛飾郡), Shimōsa (Split into Nishikatsushika District in Ibaraki Prefecture, Nakakatsushika District in Saitama Prefecture, and Higashikatsushika District in Chiba Prefecture) 1878 Katsushika District (葛飾郡), Musashi (Split into Kitakatsushika District in Saitama Prefecture and Minamikatsushika District in Tokyo Prefecture) 1878 Saitama District (埼玉郡), Musashi (Split into Kitasaitama and Minamisaitama Districts in Saitama Prefecture) 1878 Adachi District (足立郡), Musashi (Split into Kitadachi District in Saitama Prefecture and Minamiadachi District in Tokyo Prefecture) 1878 Toshima District (豊嶋郡), Musashi (Split into Kitatoshima and Minamitoshima Districts in Tokyo Prefecture) 1878 Tama District (多摩郡), Musashi (Split into Higashitama District in Tokyo Prefecture, Kitatama, Minamitama, and Nishitama Districts in Kanagawa Prefecture; the latter 3 were transferred to Tokyo Prefecture in 1893) Chūbu 1878 Kanbara District (蒲原郡), Echigo (Split into Kitakanbara, Minamikanbara, Higashikanbara, Nishikanbara and Nakakanbara Districts, and the borough (-ku) of Niigata in Niigata Prefecture) 1878 Uonuma District (魚沼郡), Echigo (Split into Kitauonuma, Nakauonuma, and Minamiuonuma Districts in Niigata Prefecture) 1878 Kubiki District (頸城郡), Echigo (Split into Higashikubiki, Nakakubiki, and Nishikubiki Districts in Niigata Prefecture) 1878 Niikawa District (新川郡), Ecchu (Split into Kaminiikawa and Shimoniikawa Districts in Toyama Prefecture) 1878 Tsuru District (都留郡), Kai (Split into Kitatsuru and Minamitsuru Districts in Yamanashi Prefecture) 1878 Yamanashi District (山梨郡), Kai (Split into Higashiyamanashi and Nishiyamanashi Districts in Yamanashi Prefecture) 1878 Yatsushiro District (八代郡), Kai (Split into Higashiyatsushiro and Nishiyatsushiro Districts in Yamanashi Prefecture) 1878 Koma District (巨摩郡), Kai (Split into Kitakoma, Nakakoma, and Minamikoma Districts in Yamanashi Prefecture) 1878 Saku District (佐久郡), Shinano (Split into Kitasaku and Minamisaku Districts in Nagano Prefecture) 1878 Takai District (高井郡), Shinano (Split into Kamitakai and Shimotakai Districts in Nagano Prefecture) 1878 Minochi District (水内郡), Shinano (Split into Kamiminochi and Shimominochi Districts in Nagano Prefecture) 1878 Ina District (伊那郡), Shinano (Split into Kamiina and Shimoina Districts in Nagano Prefecture) 1878 Chikuma District (筑摩郡), Shinano (Split into Higashichikuma and Nishichikuma Districts in Nagano Prefecture) 1878 Azumi District (安曇郡), Shinano (Split into Kitaazumi and Minamiazumi Districts in Nagano Prefecture) 1878 Ishizu District (石津郡), Mino (Split into Kamiishizu and Shimoishizu Districts in Gifu Prefecture) 1878 Shitara District (設楽郡), Mikawa (Split into Kitashitara and Minamishitara Districts in Aichi Prefecture) 1878 Kamo District (加茂郡), Mikawa (Split into Higashikamo and Nishikamo Districts in Aichi Prefecture) 1878 Kasugai District (春日井郡), Owari (Split into Higashikasugai and Nishikasugai Districts in Aichi Prefecture) Kansai 1878 Muro District (牟婁郡), Kii (Split into Kitamuro and Minamimuro Districts in Mie Prefecture and Higashimuro and Nishimuro Districts in Wakayama Prefecture) 1878 Azai District (浅井郡), Ōmi (Split into Higashiazai and Nishiazai Districts in Shiga Prefecture) 1878 Kuwata District (桑田郡), Tanba (Split into Kitakuwada and Minamikuwada Districts in Kyoto Prefecture) Shikoku 1878 Ukena District (浮穴郡), Iyo (Split into Kamiukena and Shimoukena Districts in Ehime Prefecture) 1878 Uwa District (宇和郡), Iyo (Split into Higashiuwa, Nishiuwa, Kitauwa, and Minamiuwa Districts in Ehime Prefecture) Kyushu 1878 Matsuura District (松浦郡), Hizen (Split into Higashimatsuura, Nishimatsuura, Kitamatsuura, and Minamimatsuura Districts in Nagasaki Prefecture; the former two were transferred to Saga Prefecture in 1883) 1878 Sonogi District (彼杵郡), Hizen (Split into Higashisonogi and Nishisonogi Districts, and the borough (-ku) of Nagasaki in Nagasaki Prefecture) 1878 Takaki District (高来郡), Hizen (Split into Kitatakaki and Minamitakaki Districts in Nagasaki Prefecture) 1878 Kunisaki District (国東郡), Bungo (Split into Higashikunisaki and Nishikunisaki Districts in Ōita Prefecture) 1878 Amabe District (海部郡), Bungo (Split into Kitaamabe and Minamiamabe Districts in Ōita Prefecture) 1878 Usuki District (臼杵郡), Hyūga (Split into Higashiusuki and Nishiusuki Districts in Miyazaki Prefecture) 1878 Naka District (那珂郡), Hyūga (Split into Kitanaka and Minaminaka Districts in Miyazaki Prefecture) 1878 Ōsumi District (大隅郡), Ōsumi (Split into Kitaōsumi and Minamiōsumi Districts in Kagoshima Prefecture) 1878 Soo District (囎唹郡), Ōsumi (Split into Higashisoo and Nishisoo Districts in Kagoshima Prefecture) 1878 Isa District (伊佐郡), Satsuma (Split into Kitaisa and Minamiisa Districts in Kagoshima Prefecture) Others January 1, 1879 Iwate District (磐井郡), Rikuchū (Split into Kitaiwate and Minamiiwate Districts in Iwate Prefecture) July 8, 1881 Abashiri District (網尻郡), Kushiro, Hokkaido (Merged into Abashiri District in Kitami Province) July 27, 1881 Tsugaru (津軽郡) and Fukushima (福島郡) Districts, Oshima, Hokkaido (Merged to form Matsumae District) May 9, 1883 Morokata District (諸県郡), Hyūga (Due to the split of Kagoshima Prefecture, the area became part of the new Miyazaki Prefecture becomes Kitamorokata District and parts remaining in Kagoshima Prefecture became Minamimorokata District) April 1, 1889 Samukawa District (寒川郡), Tochigi (Merged into Shimotsuga District)
1896 February 26, 1896 Nakatsu District (仲津郡), Fukuoka (Merged into Miyako District) Tsuiki (築城郡) and Kōge (上毛郡) Districts, Fukuoka (Merged to form Chikujō District) Ito (怡土郡) and Shima (志摩郡) Districts, Fukuoka (Merged to form Itoshima District) Mikasa (御笠郡), Mushiroda (席田郡), and Naka (那珂郡) Districts, Fukuoka (Merged to form Chikushi District) Kama (嘉麻郡) and Honami (穂波郡) Districts, Fukuoka (Merged to form Kaho District) Johza (上座郡), Geza (下座郡), and Yasu (夜須郡) Districts, Fukuoka (Merged to form Asakura District) Kamitsuma (上妻郡) and Shimotsuma (下妻郡) Districts, Fukuoka (Merged to form Yame District) Ikuha (生葉郡) and Takeno (竹野郡) Districts, Fukuoka (Merged to form Ukiha District) Mii (御井郡), Mihara (御原郡), and Yamamoto (山本郡) Districts, Fukuoka (Merged to form Mii District) March 26, 1896 Osumi (大住郡) and Yurugi (淘綾郡) Districts, Kanagawa (Merged to form Naka District) Mine (三根郡), Yabu (養父郡), and Kii (基肄郡) Districts, Saga (Merged to form Miyaki District) March 29, 1896 Kitakunohe (北九戸郡) and Minamikunohe (南九戸郡) Districts, Iwate (Merged to form Kunohe District) Kitaiwate (北岩手郡) and Minamiiwate (南岩手郡) Districts, Iwate (Merged to form Iwate District) Higashiwaga (東和賀郡) and Nishiwaga (西和賀郡) Districts, Iwate (Merged to form Waga District) Nishihei (西閉伊郡) and Minamihei (南閉伊郡) Districts, Iwate (Merged to form Kamihei District) Kitahei (北閉伊郡), Nakahei (中閉伊郡), and Higashihei (東閉伊郡) Districts, Iwate (Merged to form Shimohei District) Nishikatsushika District (西葛飾郡), Ibaraki (Merged into Sashima District) Kawachi (河内郡) and Shida (信太郡) Districts, Ibaraki (Merged to form Inashiki District) Toyoda (豊田郡) and Okada (岡田郡) Districts, Ibaraki (Merged into Yūki District) Koma District (高麗郡), Saitama (Merged into Iruma District) Niikura District (新座郡), Saitama (Merged into Kitaadachi District) Hatara (幡羅郡), Hanzawa (榛沢郡), and Obusuma (男衾郡) Districts, Saitama (Merged into Ōsato District) Kami (賀美郡) and Naka (那珂郡) Districts, Saitama (Merged into Kodama District) Yokomi District (横見郡), Saitama (Merged into Hiki District) Nakakatsushika District (中葛飾郡), Shimōsa, Saitama (Merged into Kitakatsushika District in Musashi Province) Asake District (朝明郡), Mie (Merged into Mie District)