Paolo Gabriele was arrested in May after police found confidential documents at his Vatican flat.
He has been charged with aggravated theft, including stealing a 100,000-euro (£78,000) cheque, while a computer analyst faces complicity charges.
The Vatican says it will continue to investigate the leaks.
Mr Gabriele admitted he was the source of leaked letters published in a controversial book by an Italian investigative journalist in May.
The bestseller, entitled His Holiness, revealed private correspondence between the Pope and his personal secretary discussing corruption and malpractice among Vatican administrators.
The Vatican called the book "criminal" and vowed to take legal action against the author, publisher, and whoever leaked the documents.
There were two surprises at the repeatedly postponed Vatican news conference finally summoned on the eve of Italy's biggest holiday of the year, Ferragosto, to announce that Paolo Gabriele is to be sent for trial.
The pope's former butler did not act alone. And Mr Gabriele was the secret source code-named Maria by the Italian investigative journalist who published some of the letters in a bestselling book earlier in the year.
No date has yet been set for the trial - which cannot begin before the end of September at the earliest because the court does not return from its summer recess until then.
There is already speculation that Mr Gabriele (who has confessed fully to investigators and has also written a private letter to Pope Benedict apologising for what he did) might be the recipient of a papal pardon before then. It is not in the interest of the Vatican to have a full-blown criminal trial in the full glare of the world's media.