- Carel Henn
- 26 hour(s):minute(s):second(s)
- Canada (Bonnyville)
The longest marathon cello playing is 26 hours, and was achieved by Carel Henn (South Africa) in Bonnyville, Alberta, Canada, from 19 to 20 December 2014.
The attempt was a fundraiser to raise funds for Bonnyvile Baptist Church.