"The Fox (What Does the Fox Say?)" is an electronic dance novelty song and viral video by Norwegian comedy duo Ylvis. The top trending video of 2013 on YouTube, "The Fox" was posted on the video-sharing website on 3 September 2013, and has received over 820 million views as of January 2019. "The Fox" peaked at the top of the Norwegian Singles Chart and was hugely successful in the United States, where it peaked at number six on the Billboard Hot 100 for three consecutive weeks, and was, before the US release of "Am I Wrong" by Nico & Vinz, the highest-ranked song by a Norwegian artist on the chart since A-ha's number-one song "Take On Me" in 1985.
Originally an "anti-hit" produced as a part of the duo's new season of Norwegian television talk show I kveld med YLVIS (Tonight with Ylvis) and uploaded on YouTube as a teaser, "The Fox", "created to fail", went viral, becoming Ylvis' "breakout" song and drawing international attention to the group. In 2013, Ylvis stated there were no plans to release an album including the song or any sequel to it.