Piero Manzoni was born on July 13, 1933, in Soncino, Lombardia, Italy to a noble family. Born as Meroni Manzoni di Chiosca e Poggiolo, he was the firstborn of Egisto Manzoni, Count of Chiosca and Poggiolo, and Valeria Meroni.
Piero had two brothers named Giuseppe and Giacomo, and two sisters, Elena and Mariuccia.
Manzoni was raised in Milan, visiting in summer Albisola Capo, a sea resort, where the Manzonis family met the founder of the Spatialism avant-garde movement Lucio Fontana. This meeting awoke the interest in art in young Piero.