Oh No They Didn't, also known as ONTD, is the largest community on LiveJournal with over 100,000 members. The community focuses on celebrity gossip and pop culture with most of its posts aggregated from other gossip blogs. The site formed a partnership with pop culture blog network Buzz Media in July 2010 that was not renewed a year later.

The blog boasted over 300,000 page views daily according to a 2008 Popmatters article, although it has considerably decreased in recent years. When LiveJournal increased the comment limit on posts from 5000 to 10,000 comments, ONTD contained the first post to reach this new limit.

The community was originally created in 2004 by teenagers Erin Lang, Bri Draffen and Breniecia Reuben.

The community published an average of 100 member posts per day, with most posts getting between 100 and 500 comments on average. The community moderators post a weekly post called "Free for All Friday" (or "FFAF") which allows members to post off-topic comments. These free-for-all posts have often been expanded to include community discussion posts for important pop culture events such as the Academy Awards, the Olympics (known as "Free for All Olympics" or "FFAO" posts) and Saturday Night Live viewing posts.

In addition to members submitting the posts themselves, ONTD relies heavily on user participation in the comments section, where members can express their opinions on posts. Members often illustrate their reaction to a particular news item by posting an animated GIF image which represents their feelings. After the death of Michael Jackson on June 25, 2009, according to MSNBC, "users expressed their collective grief by posting a Fantasia Barrino GIF, in which the American Idol star wails and flails her arms wildly," while other users expressed concern over the continued use of a popular GIF taken from the music video "Thriller" featuring a scene of Jackson eating popcorn, an image that is frequently posted on the community in anticipation of a controversial or "flame-worthy topic."

ONTD won the Best Gossip Blog award in the 2008 Weblog Awards, beating out other popular celebrity blogs such as D-Listed, Perez Hilton and TMZ, with a whopping 44% of the vote.

ONTD has been noted in O, the Oprah Magazine, cited in Life & Style, and artist Lily Allen referenced the online community in the March 2009 issue of Playboy Magazine.

The Swedish newspaper Metro described the community as "Gossip on steroids." The paper also noted that with a high volume of posts, the reader would "find a lot of highlights, and often before newspapers get their hands on it". The San Francisco Chronicle wrote that the "scandal-mongering community overflows with interactive snark" and encouraged the reader to "imagine a gossip clearinghouse run by teenagers with bad attitudes and sharp tongues". The A.V. Club cited ONTD as a "favorite time-wasting website" and wrote that "the comments section can sometimes be more amusing than the posts themselves". In December 2009, the users of ONTD were derisively referred to as "jackals" because the stories posted on the blog are taken from other sources. In response, the users embraced the term and repeatedly used the term in later posts, as well as manipulating their icons to include photographs of the animals.