As far as I know, I'm not, except my great great great grandparents or something helped to create the Atom bomb in WWII, but that's not really famous. Just answer the question truthfully.
I might be related to 4 presidents. Pierce, Lincoln, and both Bushs(unfortunately). That cause my I have family whose last name is Lincoln, and George Bushes W. mother (And his fathers wife) maiden name was Pierce. I Doubt I actually am related, but its nice to think I am!
But, hey, my grandfather bikes across America, even to Alaska, in his late 70's. Thats pretty hardcore, considering hes old as hell, and still more fit than most young people.
Wow! 70 years old and he bikes across the country. What a beast.
hmm well I guess my great great grandfather founded the University of Southern Mississippi. You could say he is pretty well known down there. Other then that I can't really think of any world famous people I could be related to.
It depends on what your version/idea of famous is. One could say that being famous is a well known national icon, where others could say that it's just a person who did a deed in the war and was considered "famous" by the troops they were with.
So I can say that I'm not related to a national icon, but I did have quite a few relatives in WWII that did some quite courageous things in battle.