This one is usually told at tech conferences, to get chuckles from the audience. That in 1899 the Head of the American Patent Office said that the patent office should be closed because everything that could be invented had been invented.
Charles Holland Duell was the the "head" of the "American Patent Office" in 1899 -- in that he was the Commissioner of the United States Patent and Trademark Office.
You know the myth is going south when they 1) can't get the title right, 2) can't name the person who supposedly did whatever the myth is about, and 3) don't even know the name of the department.
In actuality, Commissioner Duell said no such thing. If you'd like to have an actual quote he said, a good choice may be,
"In my opinion, all previous advances in the various lines of invention will appear totally insignificant when compared with those which the present century will witness. I almost wish that I might live my life over again to see the wonders which are at the threshold." *