- Who
- Eric Byrnes
- What
- 420 total number
- Where
- United States (Half Moon Bay)
- When
The most golf holes played by an individual in 24 hours (walking) is 420 holes, and was achieved by Eric Byrnes (USA) in Half Moon Bay, California, USA, on 23 April 2019.
Eric played on behalf of the Let Them Play Foundation, an organization providing scholarships to youth sports groups so they can purchase equipment, uniforms and other supplies. He used an 8-iron during the entire attempt and glow-in-the-dark golf balls. Eric walked 105 miles during the 24-hour attempt.