Japan (Officially Nippon-koku or Nihon-koku / NIPPON) is an island country in East Asia. Located in the Pacific Ocean, it lies to the east of China, Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea in the south. The characters that make up Japan's name mean "sun-origin", which is why Japan is sometimes identified as the "Land of the Rising Sun".

Japan comprises over 3,000 islands making it an archipelago. The largest islands are Honshu, Hokkaido, Kyushu and Shikoku, together accounting for 97% of Japan's land area. Most of the islands are mountainous, many volcanic; for example, Japan’s highest peak, Mount Fuji, is a volcano. Japan has the world's tenth largest population, with about 128 million people. The Greater Tokyo Area, which includes the de facto capital city of Tokyo and several surrounding prefectures, is the largest metropolitan area in the world, with over 30 million residents.

Archaeological research indicates that people were living on the islands of Japan as early as the Upper Paleolithic period. The first written mention of Japan begins with brief appearances in Chinese history texts from the first century AD.

Influence from the outside world followed by long periods of isolation has characterized Japan's history. Since adopting its constitution in 1947, Japan has maintained a unitary constitutional monarchy with an emperor and an elected parliament, the Diet.

A major economic power, Japan has the world's second largest economy by nominal GDP. It is a member of the United Nations, G8, G4, OECD and APEC, with the world's fifth largest defense budget. It is also the world's fourth largest exporter and sixth largest importer and a world leader in technology and machinery.

The English word Japan is an exonym not used in the Japanese language. The Japanese names for Japan are Nippon (????) and Nihon (???). They are both written in Japanese using the kanji ??. The Japanese name Nippon is used for most official purposes, including on Japanese money, postage stamps, and for many international sporting events. Nihon is a more casual term and the most frequently used in contemporary speech.

Both Nippon and Nihon literally mean "the sun's origin" and are often translated as the Land of the Rising Sun. This nomenclature comes from Imperial correspondence with Chinese Sui Dynasty and refers to Japan's eastward position relative to China. Before Japan had relations with China, it was known as Yamato and Hi no moto, which means "source of the sun".

The English word for Japan came to the West from early trade routes. The early Mandarin Chinese or possibly Wu Chinese word for Japan was recorded by Marco Polo as Cipangu. The modern Shanghainese (a Wu Chinese dialect) pronunciation of characters ?? (Japan) is still Zeppen [z??p?n]. The old Malay word for Japan, Jepang (modern spelling Jepun, although Indonesian has retained the older spelling), was borrowed from a Chinese language, and this Malay word was encountered by Portuguese traders in Malacca in the 16th century. It is thought the Portuguese traders were the first to bring the word to Europe. It was first recorded in English in 1577 spelled Giapan.

The early twentieth century saw a brief period of "Taisho democracy" overshadowed by the rise of expansionism and militarization. World War I enabled Japan, which joined the side of the victorious Allies, to expand its influence and territorial holdings. Japan continued its expansionist policy by occupying Manchuria in 1931. As a result of international condemnation for this occupation, Japan resigned from the League of Nations two years later. In 1936, Japan signed the Anti-Comintern Pact with Nazi Germany, joining the Axis powers in 1941.

In 1937, Japan invaded other parts of China, precipitating the Second Sino-Japanese War (1937–1945), after which the United States placed an oil embargo on Japan. On December 7, 1941, Japan attacked the United States naval base in Pearl Harbor and declared war on the United States, the United Kingdom and the Netherlands. This act brought the United States into World War II. After the atomic bombings of Hiroshima and Nagasaki in 1945, along with the Soviet Union joining the war against it, Japan agreed to an unconditional surrender on August 15 (Victory over Japan Day). The war cost Japan millions of lives and left much of the country's industry and infrastructure destroyed. The International Military Tribunal for the Far East, was convened by the Allies (on May 3, 1946) to prosecute Japanese leaders for war crimes such as the Nanking Massacre.

In 1947, Japan adopted a new pacifist constitution emphasizing liberal democratic practices. The Allied occupation ended by the Treaty of San Francisco in 1952 and Japan was granted membership in the United Nations in 1956. Japan later achieved spectacular growth to become the second largest economy in the world, with an annual growth rate averaging 10% for four decades. This ended in the mid-1990s when Japan suffered a major recession. Positive growth in the early twenty-first century has signaled a gradual recovery.