It's the record for the most game show episodes hosted by a single person.
"It's an honor to hold the Guinness World Record for hosting Jeopardy!, which I've often said is the best of reality TV," Trebek said. "We have had incredible support from our viewers for the past 30 years, and without them, I wouldn't have set this record."
Trebek began hosting the show in 1984, taking over for former host Art Fleming. Jeopardy! first appeared on television in 1964.
The series already holds a Guinness record for most Emmy Awards won by a TV game show, 29, and most Emmy wins for a producer, 11 for Harry Friedman.