What is the longest DnD game ever?

Wardhaugh is a Canadian historian known as a host of the longest uninterrupted Dungeons and Dragons campaign. As of 2022, the game is going on for 40 years, since 1982.

https://en.wikipedia.org/wiki/Robert_A._Wardhaugh#:~:text=Wardhaugh%20is%20a%20Canadian%20historian,for%2040%20years%2C%20since%201982.