Censorship in Japan has taken many forms throughout the history of the country. While Article 21 of the Constitution of Japan guarantees freedom of expression and prohibits formal censorship, effective censorship of obscene content does exist and is justified by the Article 175 of the Criminal Code of Japan. Historically, the law has been interpreted in different ways—as of 2003 it has been interpreted to mean that all pornography must be at least partly censored, and a few arrests have been made based on this law.

As of 2023, Japan is ranked 68th on the Press Freedom Index, up from 71st in the previous year. Reporters Without Borders has noted that issues concerning Japan include self-censorship among its journalists, as well as the exclusion of freelancers and foreign reporters in government events and interviews, fueling doubts about editorial independence. In 2022, an "online insults" law was introduced that would regulate the kind of speech made in the online public sphere.

As publishing became more popular in the Edo Period, the Tokugawa shogunate began to turn to censorship. During this period, the shogunate, or military government, had a constant policy to censor anything deemed as indecent by the government. Initial targets included Christianity, criticism of the shogunate, and information on the activities of the Tokugawa clan. With the Kansei Reforms, any material deemed to be disturbing the traditional way of life, as well as luxury publications, came under scrutiny. Under the Tempō Reforms, printing blocks of erotic literature, as well as the novels of Tamenaga Shunsui and Tanehiko Ryūtei were among those seized.

Their early bans focused on Christian books, military books (gunsho), mainly as a way to restrict regional daimyō from using Christianity as a political ideology and challenge the bakufu's new rule while imposing their moral authority. As military and political instability settled, the shogunate turned their gaze on social unrest. They were noting an increase in civil disobedience and satirical criticism using literature and theater coming from ordinary people. An edict for publications guidelines were issued on Kyoho 7 (1722)/11 with an outline of themes that were banned. In addition to literature, the Shogunate also placed limitations on kabuki theater actors. The shogunate prohibited women and children from appearing in plays, but this law was often ignored by theater houses. These new laws resulted in the rise of male actors who would specialize in female roles called onnagata.

After the Meiji Restoration in 1868, which marked a major political shift in Japan, the government began heavy censorship of Western ideas, pornography and any political writings critical of the Emperor of Japan and government, wanting to control the spread of information. Censorship of materials increased from this point, often using ongoing wars to increase police penalties. Episodes of newspaper suppression and imprisonment of editors occurred in 1868, 1876 and 1887. Freedom of speech and the press was heavily restricted through vaguely worded laws.

In 1930, the death penalty was added to the list of punishments deemed acceptable for certain violations. This continued, eventually to the Information and Propaganda Department (情報部, Jōhōbu) being elevated to the Information Bureau (情報局, Jōhō Kyoku) in 1940, which consolidated the previously separate information departments from the Army, Navy and Foreign Ministry under the aegis of the Home Ministry. The new Bureau had complete control over all news, advertising and public events. The following year revision of the National Mobilization Law (国家総動員法, Kokka Sōdōin Hō) eliminated freedom of the press entirely, doing things such as forcing papers in each prefecture to either merge into one paper or cease publication, with all articles by the paper having to be screened by government censors before they could be published.

On 8 February 1943, the Japanese occupiers in Shanghai created what they described as the designated area (the Shanghai ghetto) in Hongkew where they re-located and segregated the Jewish refugees in Shanghai from whom Nazi Germany had stripped citizenship. Among other abuses, Japanese authorities censored Jewish cultural activities there.

After the surrender of Japan in 1945, the Supreme Commander of the Allied Powers abolished all forms of censorship and controls on freedom of speech. Article 21 of the Constitution of Japan was later integrated in 1947 to guarantee that the Japanese had the freedom to associate with each other and express their thoughts freely. However, press censorship remained a reality during the occupation of Japan, especially in matters of pornography, and in political matters deemed subversive by the American government. Publications submitted by the press were monitored for criticisms about democracy or the problems such as starvation the Japanese citizens experienced during the occupation in the form of regulations set by The Press Code of 1945.