The longest Tennis match lasted 11 hours, 5 minutes.
The longest tennis match of all time was famously played between John Isner and Nicolas Mahut in the first round of the men’s singles at the 2010 Wimbledon. John Isner eventually won 6-4, 3-6, 6-7, 7-6, 70-68 in a match that lasted for 665 minutes (11 hours and 5 minutes), spread out over three days at the All England Club in London.