The papal tiara is a crown that was worn by popes of the Catholic Church. It was worn early in the 8th century to the mid-20th century. It (the triple tiara) was last used by Pope Paul VI in 1963. It was specifically used in Pope Paul's papal coronation.
Pope Paul, while choosing not to wear a tiara during his papacy, nevertheless never abolished the use of papal tiaras. He explicitly in his 1975 Apostolic Constitution Romano Pontifici Eligendo required that his successor be crowned. However, his successor, Pope John Paul I, after a major argument, refused to wear any tiara.