St. Mark's Day (Italian: Festa di San Marco), also known as the rosebud festival (Venetian: festa del bocolo), is a festival in Venice held on 25 April celebrating Venice's patron saint, St. Mark. On this day, men traditionally give a single rosebud to the women they love.

According to legend, the tradition originated in the 8th century, when a man of low social standing is said to have fallen in love with a noblewoman from Venice. In order to win her father's approval, he became involved in a distant war. He was mortally wounded in battle, but managed to pluck a rose from a nearby rosebush for his loved one. A companion was entrusted with returning the blood-stained rose to his lover.