The Taishō era (大正時代, Taishō jidai; [taiɕoː dʑidai] ^ⓘ) was a period in the history of Japan dating from July 30th, 1912 to December 25th, 1926, coinciding with the reign of Emperor Taishō. The new emperor was a sickly man, which prompted the shift in political power from the old oligarchic group of elder statesmen (or genrō) to the Imperial Diet of Japan and the democratic parties. Thus, the era is considered the time of the liberal movement known as Taishō Democracy; it is usually distinguished from the preceding chaotic Meiji era and the following militaristic-driven first part of the Shōwa era.

The two kanji characters in Taishō (大正) were from a passage of the Classical Chinese I Ching: 大亨以正 天之道也 (translated: "Great prevalence is achieved through rectitude, and this is the Dao of Heaven.") The term could be roughly understood as meaning "great rectitude", or "great righteousness".

On 30 July 1912, Emperor Meiji died and Crown Prince Yoshihito succeeded to the throne as Emperor of Japan. In his coronation address, the newly enthroned Emperor announced his reign's nengō (era name) Taishō, meaning "great righteousness".

The end of the Meiji period was marked by huge government, domestic, and overseas investments and defense programs, nearly exhausted credit, and a lack of foreign reserves to pay debts. The influence of Western culture experienced in the Meiji period also continued. Notable artists, such as Kobayashi Kiyochika, adopted Western painting styles while continuing to work in ukiyo-e; others, such as Okakura Kakuzō, kept an interest in traditional Japanese painting. Authors such as Mori Ōgai studied in the West, bringing back with them to Japan different insights on human life influenced by developments in the West.

The events following the Meiji Restoration in 1868 had seen not only the fulfillment of many domestic and foreign economic and political objectives—without Japan suffering the colonial fate of other Asian nations—but also a new intellectual ferment, in a time when there was worldwide interest in communism and socialism and an urban proletariat was developing. Universal male suffrage, social welfare, workers' rights, and nonviolent protests were ideals of the early leftist movement.^{[citation needed]} Government suppression of leftist activities, however, led to more radical leftist action and even more suppression, resulting in the dissolution of the Japan Socialist Party (日本社会党, Nihon Shakaitō) only a year after its founding and general failure of the socialist movement in 1906.^{[citation needed]}

The beginning of the Taishō period was marked by the Taishō political crisis in 1912–13 that interrupted the earlier politics of compromise. When Saionji Kinmochi tried to cut the military budget, the army minister resigned, bringing down the Rikken Seiyūkai cabinet. Both Yamagata Aritomo and Saionji refused to resume office, and the genrō were unable to find a solution. Public outrage over the military manipulation of the cabinet and the recall of Katsura Tarō for a third term led to still more demands for an end to genrō politics. Despite old guard opposition, the conservative forces formed a party of their own in 1913, the Rikken Dōshikai, a party that won a majority in the House over the Seiyūkai in late 1914.

On February 12, 1913, Yamamoto Gonnohyōe succeeded Katsura as prime minister. In April 1914, Ōkuma Shigenobu replaced Yamamoto.

Crown Prince Yoshihito married Sadako Kujō on 10 May 1900. Their coronation took place on November 11, 1915.