The Shinkansen (Japanese: 新幹線, pronounced [ɕiŋkaꜜɰ̃seɴ], lit. 'new main line'), colloquially known in English as the bullet train, is a network of high-speed railway lines in Japan. Initially, it was built to connect distant Japanese regions with Tokyo, the capital, to aid economic growth and development. Beyond long-distance travel, some sections around the largest metropolitan areas are used as a commuter rail network. It is operated by five Japan Railways Group companies.

Over the Shinkansen's 50-plus-year history, carrying over 10 billion passengers, there has been not a single passenger fatality or injury on board due to derailments or collisions.Starting with the Tōkaidō Shinkansen (515.4 km, 320.3 mi) in 1964, the network has expanded to currently consist of 2,764.6 km (1,717.8 mi) of lines with maximum speeds of 240–320 km/h (150–200 mph), 283.5 km (176.2 mi) of Mini-Shinkansen lines with a maximum speed of 130 km/h (80 mph), and 10.3 km (6.4 mi) of spur lines with Shinkansen services. The network presently links most major cities on the islands of Honshu and Kyushu, and Hakodate on northern island of Hokkaido, with an extension to Sapporo under construction and scheduled to commence in March 2031. The maximum operating speed is 320 km/h (200 mph) (on a 387.5 km section of the Tōhoku Shinkansen). Test runs have reached 443 km/h (275 mph) for conventional rail in 1996, and up to a world record 603 km/h (375 mph) for SCMaglev trains in April 2015.The original Tōkaidō Shinkansen, connecting Tokyo, Nagoya and Osaka, three of Japan's largest cities, is one of the world's busiest high-speed rail lines. In the one-year period preceding March 2017, it carried 159 million passengers, and since its opening more than five decades ago, it has transported more than 5.6 billion total passengers. At peak times, the line carries up to 16 trains per hour in each direction with 16 cars each (1,323-seat capacity and occasionally additional standing passengers) with a minimum headway of three minutes between trains.Japan's Shinkansen network had the highest annual passenger ridership (a maximum of 353 million in 2007) of any high-speed rail network until 2011, when the Chinese high-speed railway network surpassed it at 370 million passengers annually, reaching over 2.3 billion annual passengers in 2019.