Over 6,000 of the medals had been produced by the Italian state mint, in gold, silver and bronze and placed on sale at the Vatican Publishing House in St. Peter's Square, before the mistake was discovered.
The medals were commissioned to celebrate Pope Francis's first year in office, and were to carry his offical motto round the side: "Vidit ergo Jesus publicanum et quia miserando antque eligendo vidit, ait illi sequere me" - meaning "Jesus therefore sees the tax collector, and since he sees by having mercy and by choosing, he says to him, follow me."
Instead, though, the inscription refers to 'Lesus'.
When the news was announced by the Catholic News Service, Twitter users were amused. "I blame the Lesuits," commented one. But it's an understandable mistake: Latin lacks the letter 'J', which is represented instead by the letter 'I' - easily confused with an 'L'.
A handful of the medals had already been sold before the mistake was discovered - and the purchasers are likely to make a nice profit if they choose to sell.
Perhaps the most notorious printing error in history, though, is another one associated with Christianity. Back in 1631, a Bible was printed in London in which one of the Ten Commandments read: "Thou shalt commit adultery".
Most copies of the so-called Wicked Bible were burned as soon as the mistake was discovered, but a small number escaped. Two years ago, one was advertised for sale at $89,000.