- Utah Undie Run 2011
- 2270 people
- United States (Salt Lake City)
The largest gathering of people wearing only underwear was achieved by 2,270 participants (all USA) at the Utah Undie Run in Salt Lake City, Utah, USA, on 24 September 2011. Participants were gathered in a single area in accordance with guidelines before the run itself began. The event was organised to challenge the perception that Utah is an "uptight" state.