Pacelli () is an Italian surname derived from the medieval given name Pacello. Notable people with the surname include:
Asprilio Pacelli (1570–1623), Italian composer Ernesto Pacelli (died 1925), Vatican financial adviser, cousin of Pius XII Eugenio Pacelli (1876–1958), head of the Catholic Church as Pope Pius XII Francesco Pacelli (1872–1935), Vatican lawyer, elder brother of Pius XII Frank Pacelli (1924–1997), American TV personality James Martin Pacelli McGuinness (1950–2017), Irish politician and statesman Matteo Pacelli (died 1731), Italian painter Vincent "Vinny Basile" Pacelli, American Mafioso indicted in Operation Old Bridge William V. Pacelli (1893–1942), American politician
See also Pacelli High School Cardinal Pacelli School