|Area||227,960 km2 (88,020 sq mi)|
|Length||1,300 km (810 mi)|
|Width||50–230 km (31–143 mi)|
|Coastline||10,084 km (6265.9 mi)|
|Highest elevation||3,776 m (12388 ft)|
|Highest point||Mount Fuji|
|Largest settlement||Tokyo (pop. 14,043,239)|
|Pop. density||447/km2 (1158/sq mi)|
Honshu (本州, Honshū, pronounced [hoꜜɰ̃ɕɯː] i; lit. 'main island'), historically called Akitsushima (秋津島, lit. 'Dragonfly island'), is the largest and most populous island of Japan.  It is located south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Straits. The island separates the Sea of Japan, which lies to its north and west, from the North Pacific Ocean to the south and east. It is the seventh-largest island in the world, and the second-most populous after the Indonesian island of Java.
Honshu had a population of 104 million as of 2017[update], constituting 81.3% of the entire population of Japan, and mostly concentrated in the coastal areas and plains. Approximately 30% of the total population resides in the Greater Tokyo Area on the Kantō Plain. As the historical center of Japanese cultural and political power, the island includes several past Japanese capitals, including Kyōto, Nara and Kamakura. Much of the island's southern shore forms part of the Taiheiyō Belt, a megalopolis that spans several of the Japanese islands. Honshu contains Japan's highest mountain, Mount Fuji, and its largest lake, Lake Biwa.
Most of Japan's industry is located in a belt running along Honshu's southern coast, from Tokyo to Nagoya, Kyōto, Osaka, Kobe, and Hiroshima; by contrast, the economy along the northwestern Sea of Japan coast is largely based on fishing and agriculture. The island is linked to the other three major Japanese islands by a number of bridges and tunnels. The island primarily shares two climates, with Northern Honshu being mainly humid continental climate while the south has a humid subtropical climate.
The name of the island, Honshū (本州), directly translates to "main province" in English.
Humans first arrived in Honshu about 60,000 years ago. 
Honshu was the target of devastating air raids during the Pacific War of World War II. The first air raid to strike Honshu and the other home islands was the Doolittle Raid. With the introduction of the Boeing B-29 Superfortress, the firebombing of Tokyo culminated in Operation Meetinghouse, the most destructive air raid in human history, which destroyed 16 square miles (41 km2; 10,000 acres) of central Tokyo, leaving an estimated 100,000 civilians dead, and over one million homeless. The war ended with the atomic bombings of Hiroshima and Nagasaki shortly before Japan's surrender and signing of the Japanese Instrument of Surrender on September 2, 1945, on board the USS Missouri (BB-63) in Tokyo Bay.
The island is roughly 1,300 km (810 mi) long and ranges from 50 to 230 km (31 to 143 mi) wide, and its total area is 227,960 km2 (88,020 sq mi), making it slightly larger than the island of Great Britain 209,331 km2 (80,823 sq mi). Its land area has been increasing with land reclamation and coastal uplift in the north due to plate tectonics with a convergent boundary. Honshu has 10,084 kilometres (6,266 mi) of coastline.
Mountainous and volcanic, Honshu experiences frequent earthquakes (the Great Kantō earthquake heavily damaged Tokyo in September 1923, and the earthquake of March 2011 moved the northeastern part of the island by varying amounts of as much as 5.3 m (17 ft) while causing devastating tsunamis). The highest peak is the active volcano Mount Fuji at 3,776 m (12,388 ft), which makes Honshu the world's 7th highest island. There are many rivers, including the Shinano River, Japan's longest. The Japanese Alps span the width of Honshu, from the 'Sea of Japan' coast to the Pacific shore. The climate is generally humid subtropical in western Japan and humid continental in the north.
Honshu has a total population of 104 million people, according to a 2017 estimate, 81.3% of the entire population of Japan. The largest city is Tokyo (population: 13,988,129), the capital of Japan and part of the Greater Tokyo Area, the most populous metropolitan area in the world.
Honshu is connected to the islands of Hokkaidō, Kyūshū and Shikoku by tunnels and bridges. Three bridge systems have been built across the islands of the Inland Sea between Honshu and Shikoku (Akashi Kaikyō Bridge and the Ōnaruto Bridge; Shin-Onomichi Bridge, Innoshima Bridge, Ikuchi Bridge, Tatara Bridge, Ōmishima Bridge, Hakata–Ōshima Bridge, and the Kurushima-Kaikyō Bridge; Shimotsui-Seto Bridge, Hitsuishijima Bridge, Iwakurojima Bridge, Yoshima Bridge, Kita Bisan-Seto Bridge, and the Minami Bisan-Seto Bridge), the Seikan Tunnel connects Honshu with Hokkaidō, and the Kanmonkyo Bridge and Kanmon Tunnel connects Honshu with Kyūshū.
These are notable flora and fauna of Honshu.
|Japanese black bear||Fauna||A subspecies of the Asian black bear. It is typically herbivorous and lives in Honshu and Kyushu.|
|Japanese macaque||Fauna||(Macaca fuscata or snow monkey), is a terrestrial Old World monkey species that is native to Japan.|
|Japanese golden eagle||Fauna||(Aquila chrysaetos japonica), a subspecies of the golden eagle, inhabits Honshu and Hokkaido all year round.|
|Japanese wolf||Fauna||Aka Honshu Wolf is an extinct subspecies of the wolf.|
|Sika Deer||Fauna||Cervus nippon (Japanese deer), is overabundant in Honshu.|
|Japanese dwarf flying squirrel||Fauna||(Nihon momonga) is one of two species of Old World flying squirrels in the genus Pteromys.|
|Japanese raccoon dog||Fauna||(Nyctereutes viverrinus, also called tanuki), is a species of canid endemic to Japan.|
|Japanese giant salamander||Fauna||(Andrias japonicus) this fully aquatic salamander is endemic to Japan and called Ōsanshōuo (Giant Salamander)|
|Takydromus tachydromoides||Fauna||The Japanese grass lizard, is a wall lizard species of the genus Takydromus.|
|Japanese serow||Fauna||(kamoshika, lit. "coarse pelt deer"): (Capricornis crispus) is a Japanese goat-antelope found in dense woodland primarily in northern and central Honshu.|
|Japanese giant flying squirrel||Fauna||(musasabi, Petaurista leucogenys) is native to Japan where it inhabits sub-alpine forests and boreal evergreen forests on Honshu, Shikoku and Kyushu.|
|Japanese boar||Fauna||(Sus scrofa leucomystax, aka white-moustached pig, Nihon-inoshishi (ニホンイノシシ)), is a subspecies of wild boar native to all of Japan, save for Hokkaido and the Ryukyu Islands.|
|Japanese bush warbler||Fauna||(uguisu (鶯), is an Asian passerine bird more often heard than seen. It's a year-round resident of Japan (except Hokkaido where it is only in summer).|
|Sasakia charonda||Fauna||National butterfly of Japan (ō-murasaki, "great purple")|
|Copper pheasant||Fauna||(Syrmaticus soemmerringii) a large pheasant with a rich coppery chestnut plumage is endemic to Japan.|
|Green pheasant||Fauna||(Phasianus versicolor), aka Japanese green pheasant, is an omnivorous bird native to the Japanese archipelago, to which it is endemic.|
|Grey Heron||Fauna||(Ardea cinerea) Long legged wading bird.|
|Japanese scops owl||Fauna||(Otus semitorques) is a resident breeder in Japan and found in other countries in East Asia.|
|Doryrhamphus japonicus||Fauna||Doryrhamphus japonicus, or the Honshu pipefish, is a species of flagtail pipefish|
|Brahmaea japonica||Fauna||(Japanese owl moth) a species of moth of the Brahmaeidae family native to Japan.|
|Japanese spider crab||Fauna||(Macrocheira kaempferi) a marine crab with the largest leg-span of any arthropod. They live off the southern coasts of Honshū from Tokyo Bay to Kagoshima Prefecture.|
|Chum salmon||Fauna||(aka white salmon (白鮭 シロサケ) is native to middle and northern Honshu, Hokkaido and the North Pacific.|
|Silurus biwaensis||Fauna||The giant Lake Biwa catfish or Biwako-o'namazu, endemic to Lake Biwa.|
|Oncorhynchus kawamurae||Fauna||A species of landlocked Pacific trout in Japan. It's endemic to Lake Tazawa, Akita Prefecture, but was translocated to Lake Saiko.|
|Akita Inu||Fauna||(秋田犬, Akita-inu) is a historic dog breed of large size originating from the mountains in Akita Prefecture (northern Honshu).|
|Kai Ken||Fauna||The Kai Ken (甲斐犬) is a rare breed of dog native to Japan. It is originally from Kai Province in Yamanashi Prefecture.|
|Kishu||Fauna||Kishu Ken are a rare dog breed that was selectively bred for the hunting of wild boar and deer in the mountainous Mie prefecture and Wakayama prefecture.|
|Shiba Inu||Fauna||The Shiba Inu (柴犬), is an original and distinct spitz breed hunting dog, native to Japan.|
|Japanese rose||Flora||(Rosa rugosa), a species of rose native to eastern Asia and Japan.|
|Hydrangea hirta||Flora||A species of flowering plant in the family Hydrangeaceae that is native to East Asia and common in the Pacific side of Honshu.|
|Tsuga sieboldii||Flora||(Tsuga sieboldii or simply tsuga (栂)), is a conifer native to the Japanese islands of Honshū, Kyūshū, Shikoku and Yakushima.|
See also: Category:Volcanoes of Honshu
Being on the Ring of Fire, the island of Honshu is seismically active, and is home to 40 active volcanoes.
In 2011, an earthquake of magnitude 9.0–9.1 occurred off the coast of Honshu, generating tsunami waves up to 40.5 meters (133 ft) high and killing 19,747. It was the most powerful earthquake ever recorded in Japan, and the fourth most powerful earthquake in the world since modern record-keeping began in 1900. The tsunami subsequently led to the meltdown of 3 nuclear reactors at the Fukushima Daiichi Nuclear Power Plant, leading to the Fukushima nuclear disaster.
|Minami Alps National Park||南アルプス|
|Chūbu-Sangaku National Park||中部山岳|
|Hakusan National Park||白山|
|Myōkō-Togakushi Renzan National Park||妙高戸隠連山|
|Daisen-Oki National Park||大山隠岐|
|Chichibu Tama Kai National Park||秩父多摩甲斐|
|Fuji-Hakone-Izu National Park||富士箱根伊豆|
|Jōshin'etsu-kōgen National Park||上信越高原|
|Nikkō National Park||日光国立公園|
|Ogasawara National Park||小笠原|
|Ise-Shima National Park||伊勢志摩|
|Sanin Kaigan National Park||山陰海岸|
|Yoshino-Kumano National Park||吉野熊野|
|Setonaikai National Park||瀬戸内海|
|Bandai-Asahi National Park||磐梯朝日|
|Sanriku Fukkō National Park||三陸復興|
|Towada-Hachimantai National Park||十和田八幡平|
|Oze National Park||尾瀬|
|Region||List of Quasi-National Parks|
|Tōhoku||Shimokita Hantō , Tsugaru , Hayachine, Kurikoma, Minami-Sanriku Kinkazan , Zaō, Oga, Chōkai|
|Kantō||Suigo-Tsukuba, Minami Bōsō, Meiji no Mori Takao, Tanzawa-Ōyama|
|Chūbu||Echigo Sanzan-Tadami, Myōgi-Arafune-Saku Kōgen, Sado-Yahiko-Yoneyama, Noto Hantō, Echizen-Kaga Kaigan, Yatsugatake-Chūshin Kōgen, Tenryū-Okumikawa, Chūō Alps, Ibi-Sekigahara-Yōrō, Hida-Kisogawa, Aichi Kōgen, Mikawa Wan|
|Kansai||Suzuka, Wakasa Wan, Tango-Amanohashidate-Ōeyama, Biwako, Murō-Akame-Aoyama, Kongō-Ikoma-Kisen, Yamato-Aogaki, Kōya-Ryūjin, Meiji no Mori Minō, Kyoto Tamba Kogen|
|Chūgoku||Hyōnosen-Ushiroyama-Nagisan, Hiba-Dōgo-Taishaku, Nishi-Chūgoku Sanchi, Kita Nagato Kaigan, Akiyoshidai|
Honshu island generates around US$3.5 trillion or more than 80% of Japan's GDP.
Fruit, vegetables, grains, rice and cotton make up the main produce grown in Honshu. The Tohoku region, spanning the north-eastern part of the island, is notable for its rice production, with 65% of cultivated land being rice paddy fields – almost a quarter of all paddy fields in Japan. Chiba Prefecture is famous for its peanuts, also being the largest producer in Japan. Rare species of the lichen genus Menegazzia are found only in Honshu.
Most of Japan's tea and silk is from Honshu. Japan's three largest industrial regions are all located on Honshu: the Keihin region, the Hanshin Industrial Region, and the Chūkyō Industrial Area.
Honshu is home to a large portion of Japan's minimal mineral reserves, including small oil and coal deposits. Several coal deposits are located in the northern part of the island, concentrated in Fukushima Prefecture and Niigata Prefecture, though Honshu's coal production is negligible in comparison to Hokkaido and Kyushu. Most of Japan's oil reserves are also located in northern Honshu, along the west coast, spanning Niigata, Yamagata and Akita Prefectures.
Most of Japan's copper, lead, zinc and chromite is located on Honshu, along with smaller, scattered deposits of gold, silver, arsenic, sulfur and pyrite.
The Tokaido Shinkansen, opened in 1964 between Tokyo and Shin-Ōsaka, is Japan's first high-speed rail line. It is the world's oldest high-speed rail line and one of the most heavily used. The San'yō Shinkansen, connects the two largest cities in western Japan, Shin-Osaka in Osaka with Hakata Station in Fukuoka. Both the Tokaido Shinkansen and the Sanyo Shinkansen help form a continuous high-speed railway through the Taiheiyō Belt megalopolis.
The island is divided into five nominal regions and contains 34 prefectures, including metropolitan Tokyo. Administratively, some smaller islands are included within these prefectures, notably including the Ogasawara Islands, Sado Island, Izu Ōshima, and Awaji Island.
The regions and their prefectures are:
MILT classification 6,852 islands(main islands: 5 islands, remote islands: 6,847 islands)
1945: In the single deadliest air raid of World War II, 330 American B-29s rain incendiary bombs on Tokyo, touching off a firestorm that kills upwards of 100,000 people, burns a quarter of the city to the ground, and leaves a million homeless.