The crucifix of San Marcello is a medieval work of religious art that is venerated in the Oratory of Santissimo Crocifisso of the Church of San Marcello al Corso in Rome. Having survived a fire that destroyed the church in 1519, the crucifix was popularly believed to possess intercessory powers. During an epidemic of plague in 1522 the crucifix was carried in a procession through the city. According to popular belief at the time, the procession caused the plague to leave the neighborhoods through which the crucifix passed, and eventually to die out in Rome.
Because contemporaries then believed that the crucifix had proven its spiritual efficacy twice, a confraternity was set up which quickly became one of the largest in Rome. The procession of 1522 is considered by some scholars to be the origin of modern Holy Thursday processions held annually in Catholic cities, and the crucifix itself is still part of modern Roman religious processionary, particularly at Easter, although also at times of emergency. Pope Francis had it brought to St Peter's Square on several occasions during the COVID-19 pandemic in March 2020.