Shapiro (also Schapiro, Shapira, Spiro, Spira, etc.)
Is a Jewish last name, taken by fomer residents of the city of Shpeyer in Bavaria (XI-XIV centuries), one of the most important Jewish religious centers of Europe at that time.
The community was reportedly destroyed by the crusaders and its members spread all over eastern-central Europe (Russia, Poland, Lithuania, Bohemia, etc.).
Also, the word shapira in Aramaic means "something beautiful", from the hebrew word "sapir" or safire.
Shapiro is one of three Ashkenazic last names that have a known "yichus" (credible family line) as Kohanim, members of the Jewish priestly clan, descendants of Aharon, Moses brother and first high priest.
It must be noted that, while being a Shapiro doesn't automatically render you a kohen (you must have a 3-generation family tradition), it does mean you have a high chance of being one.