Do you have to be a resident to become a member of the supreme court?

You don't have to be a resident...or a citizen...a graduate of America's finest law school...a sitting judge...or even attended college to be a Justice on the Supreme Court. The only requirement, according to the Constitution, for a person to take a seat on the Supreme Court that person must be nominated by the president and approved by the Senate. That's it! George W. Bush wanted to seat Harriet Miers, who'd never been a judge but was a lawyer. The Senate reported they were planning to not approve her because she'd never been a judge...but if a hog farmer or a diesel mechanic who never graduated from high school (a couple of Justices in the 19th century were high school dropouts who learned the law from reading books, so it's possible) could prove they had the greatest legal mind of all time to the satisfaction of the president and the Senate, the Supreme Court would seat that person.

In today's legal environment that wouldn't happen because America has enough sitting judges they don't need to look outside their ranks for new Supreme Court Justices, but there's no law that says they can't still do it.