An Undie Run is an event where a large number of people disrobe until they are only wearing underwear, and then run. The site of Undie Runs are typically college campuses, but they may occur on other sites such as streets. Undie Runs may be purely for entertainment, a form of protest, or as with the ASU Undie Run, fund-raising for charitable purposes. It is reported that the Guinness Book of World Records considers the Undie Run that took place on September 24, 2011, in Salt Lake City, Utah, United States to have had a record number of participants. There were 2,270 participants in that Undie Run, which was held to protest Utah's conservative laws. COED Magazine, a magazine in the United States marketed to college students, has reported that Undie Runs are the "number one university sanctioned event".
Universities in the United States with Undie Run traditions
- California State University, Fullerton
- Chapman University
- Colorado State University
- Northeastern University
- University of Florida
- San Diego State University
- University of California, Santa Barbara
- University of California, Davis
- University of California, San Diego
- University of California, Los Angeles
- University of California, Riverside
- University of Montana – Missoula
- Arizona State University(ended 4/28/15) 
- University of Arizona
- University of Kentucky
- University of Oregon (Presented by the Emerald Media Group and the Duck Store)
- Shyong, Frank (September 15, 2011). "Fountain removed, but not for Undie Run". The Orange County Register. Retrieved 8 October 2011.
- "Salt Lake City underwear run sets world record". The Sacramento Bee. Associated Press. October 6, 2011. Retrieved 8 October 2011.
- Stevens, John (26 September 2011). "Thousands run through the streets of Salt Lake City in their underwear to protest against Utah 'being so uptight'". Daily Mail. Associated Newspapers Ltd. Retrieved 30 March 2012.
- "The Top 10 University Sanctioned Events". COED Magazine. September 5, 2010. Retrieved 8 October 2011.
- "Undie Run tradition faces growing pains".
- "UCSB kicks Undie Run off campus".
- "Undie dash moonlights tonight across campus". The Independent Florida Alligator. September 30, 2011. Retrieved 8 October 2011.
- Radich, Sean. "Weekly Washup 26 September 2011". Australia's Surfing Life. Retrieved 8 October 2011.
- Bates, Michael (26 September 2011). "Stupid, Fun, Traditions". The Bottom Line. Retrieved 8 October 2011.
- "Going Au Natural All Over Campus". March 30, 2008.
|last1=in Authors list (help)
- Kivowitz Boatright-Simon, Elizabeth (July 29, 2009). "UCLA ends student Undie Run due to safety concerns". UCLA Newsroom. University of California, Los Angeles. Retrieved 8 October 2011.
- Moy, Chelsi (September 18, 2011). "Conduct code directs how University of Montana deals with streakers, shooters". Missoulian. Retrieved 8 October 2011.
- http://www.statepress.com/article/2015/04/asu-has-image-problems-undie-run-isnt-one-of-them. Missing or empty
- Hendly, Matthew (May 3, 2011). "Arizona State University's 'Undie Run' Trying to Break World Record for Most Drunk and Naked College Students...Or Something Like That". Phoenix New Times. Retrieved 8 October 2011.
- Libman, KC (October 25, 2012). "Stripping for a cause: my experience at ZonaZoo's Undie Run". The Daily Wildcat. Retrieved 23 May 2014.
- "UK Undie Run". Retrieved 9 February 2013.