alt.revisionism is a Usenet newsgroup intended for discussion of the controversial topic of Holocaust revisionism. Although the name of the newsgroup suggests that all forms of historical revisionism can be discussed there, the vast majority of discussion (and flame wars) centers on the Holocaust.

The newsgroup is noteworthy for sparking one of the most successful and well-known campaigns of anti-censorship on the Internet. Because the topic of Holocaust revisionism is so controversial (in fact, it is illegal in several countries), a number of organizations (such as the Simon Wiesenthal Center) have made attempts to stop Holocaust revisionism by suppressing it. This campaign has spread to the Internet, where numerous revisionist and white supremacist Web sites have been shut down because of their content.

Beginning in the early 1990s, the members of alt.revisionism took a different approach to the subject of revisionism. Instead of trying to suppress the revisionists on the newsgroup, regular newsgroup participants such as Ken McVay and Jamie McCarthy, working on the principle that the best antidote to a bad argument is a better one, began researching the claims of the revisionists to prove them wrong. They posted their historical findings to the newsgroup and began archiving documents at various Internet sites. McVay in particular dedicated a great deal of his time to making historical documents available online through his Nizkor Project.

When faced with such detailed essays and works as McVay's detailed debunking of the revisionist publication 66 Questions and Answers About The Holocaust, the pro-revisionist participants in the newsgroup found it harder and harder to state a legitimate case for Holocaust revisionism. Many of their offered documents and pieces of evidence were found to be misstated, poorly researched, and often outright lies and falsehoods. The revisionists eventually gave up trying to debate the anti-revisionist faction on the newsgroup, and instead they began an ever-increasing number of personal attacks, slanderous (and occasionally libelous) writings and newsgroup postings, and even occasional death threats.

The newsgroup has been the target of several denial of service attacks, spam floods, and other hacking attempts.

The information content of alt.revisionism has dissolved to nearly nil since the advent of the World Wide Web. However, the flame wars and incessant personal attacks by the revisionist crowd on the newsgroup against the historical evidence of their foes has provided a source of entertainment for many kook watchers. Critics of Holocaust revisionism cite alt.revisionism as an expression of its true face.