Was Hitler of Jewish blood. Did he actually have a verifiable ancestor
that was Jewish?

Dear One God, 

First of all, as some have mentioned before, even if you have "Jewish
blood" (whatever that means, Jews have the same blood as the rest of
us...), that doesn't make a Jew.

However, Hitler had no verifiable ancestor that was Jewish. The
Holocaust History site states:
" Few, if any, of the reputable historians on the Holocaust believe
that this is so. It is more likely that Hitler tried to keep the murky
history of his family quite secret because there was a high incidence
of insanity and feeble-mindedness in his ancestors."
(SOURCE: The HOlocaust History Page,
<http://www.holocaust-history.org/questions/hitler-jewish.shtml>).

The also recommend the first chapter of the following book, that
disproves this rumour through research:
Werner Maser, _Hitler: Legend, Myth & Reality_. 

I hope this answers your question. Please contact me if you need any
clarification on this answer before you rate it. My search term:
[Was Hitler Jewish?]

The best answer that I've found is that Hitler *probably* had no
Jewish ancestors.  The uncertainty arises from the fact that his
grandfather, Alois, was registered as an illegitimate child.  Alois'
mother worked for a wealthy Jewish family and there is some
speculation that she had an affair with a member of that family. 
However, most sources I've seen regard this as very unlikely.

Hope this helps.

See, e.g., http://www.jewishvirtuallibrary.org/jsource/Holocaust/hitlerjew.html;
http://www.straightdope.com/classics/a3_325b.html.

We all have Jewish ancestors. Just unverifiable.

I'm not Jewish so excuse the ignorance but...

Don't Jews believe in the Old Testament?
Doesn't the Old Testament say we all came from Adam?

By definition does this not make us all Jewish? (Practicing Jew or not!)

Sort of.  To be Jewish your mother must have been Jewish.

hi there canadian ...

true enough, as far as it goes. And scubajim is right, judaism is
traditionally passed down via the mother, not the father -- but then
we're all descendents of eve, so... the real answer is that adam & eve
weren't  'jewish,' as such -- jews a distinct
people/nation/religion/what-have-you only come in with abraham, about
a dozen chapters later in genesis. abe and sarah, his wife are the
first jews.

note that means that there are people out there - adam, eve, noah,
etc. - who have a personal relationship with god -- good enough to
chat with him! -- even though they're not jewish. that didn't stop
with abraham. non-jews have a relationship with god, too, according to
judaism!

hope this sheds light,
roger