The 'Not The Onion' meme stems from a popular subreddit and internet culture dedicated to news headlines that sound like satire but are completely factual. Named after 'The Onion,' the world's most famous satirical news outlet, this meme category highlights the 'truth is stranger than fiction' phenomenon. It gained widespread popularity as the news cycle became increasingly surreal, providing a shorthand for users to express disbelief that a story is genuine. The meme is typically used by sharing a screenshot of a legitimate news source alongside a stamp or caption that clarifies its reality, effectively mocking the absurdity of modern life.