What is the title of the first book printed using movable type in Europe?

The first major book printed in Europe using mass-produced metal movable type was the Gutenberg Bible. Johannes Gutenberg produced the Latin Vulgate Bible in Mainz, in the Holy Roman Empire, during the 1450s.

Also called the 42-line Bible, the book takes its name from the usual number of lines on each page. Gutenberg’s achievement was not the invention of writing or even of printing itself—woodblock printing existed earlier, and movable type had been used in East Asia—but the development of an efficient European system using reusable metal type, suitable ink, and a press.

The Bible’s production helped launch the Gutenberg Revolution and transformed the spread of books and ideas in Western Europe. Despite its mechanical production, the edition was designed with the visual standards of a manuscript Bible, including decorated initials and carefully balanced pages.

The Diamond Sutra is older and was printed in China in 868, but it was made with woodblocks rather than the European metal movable-type process named in the question. The Gutenberg Bible is therefore the standard answer, although scholars debate details about the earliest European printed works.