Until the Meiji Restoration, the area of Aomori prefecture was known as the northern part of Mutsu Province.
During the Edo period the Hirosaki clan began building a seaport at the current city of Aomori. There were green woods near the city which were used as landmarks for the ships that came into port. These green woods called aoi-mori is where Aomori got its name. The prefecture came into existence in 1871. The town of Aomori was established in 1889. The town was incorporated as a city in 1898 with a population of 28,000. On May 3, 1910, a fire broke out in the
Yasukata district. Fanned by strong winds, the fire quickly devastated the whole city. The conflagration claimed 26 lives and injured a further 160 residents. It destroyed 5,246 houses and burnt 19 storage sheds and 157 warehouses. At 10:30 p.m. on July 28, 1945, a squadron of American B29 bombers bombed over 90% of the city.
Radio Aomori (RAB) made its first broadcast in 1951. Four years later, the first fish auctions were held. 1958 saw the completion of the Municipal Fish Market as well as the opening of the Citizen's Hospital. In the same year, the Tsugaru Line established a rail connection with
Minmaya Village at the tip of the peninsula.
Various outlying towns and villages were incorporated into the growing city and with the absorption of Nonai Village in 1962, Aomori became the largest city in the prefecture.
In March 1985, after 23 years of labor and a financial investment of 700 billion yen, the Seikan Tunnel finally linked the islands of Honshū and Hokkaidō, thereby becoming the longest tunnel of its kind in the world. Almost exactly three years later, on March 13, railroad service was inaugurated on the Tsugaru Kaikyo Line.
That same day saw the end of the Seikan ferry rail service. During their 80 years of service, the familiar ferries of the Seikan line sailed between Aomori and Hakodate some 720,000 times, carrying 160 million passengers.
In April 1993, Aomori Public College opened. In August 1994, Aomori City made an "Education, Culture and Friendship Exchange Pact" with Kecskemét in Hungary. One year later, a similar treaty was signed with Pyongtaek in South Korea, and cultural exchange activities began with exchanges of woodblock prints and paintings.
In April 1995, Aomori Airport began offering regular international air service to Seoul, South Korea, and Khabarovsk, Russia; however, the flights to Khabarovsk were discontinued in 2004.
In June 2007, four North Korean defectors reached Aomori Prefecture, after having been at sea for six days, marking the second known case ever where defectors have successfully reached Japan by boat.
In March 2011, a magnitude 9.0 earthquake struck Japan on the east coast. The northeastern coast of Aomori Prefecture was affected by the resulting tsunami. Buildings along harbors were damaged along with boats thrown about in the streets.