How long has Alex Trebek been host of Jeopardy?

Since the show began as a syndicated nighttime show on September 10 1984 or over 25 years

26 Years

Alex Trebek started hosting Jeopardy with the first syndicated nighttime show on September 10 1984
Alex Trebek has hosted Jeopardy since the syndicated show began 27 seasons ago in 1984.