Giangiacomo is an Italian given name, a combination of the names Gian and Giacomo. Notable people with the name include:
Giangiacomo Borghese (1889–1954), Italian politician, fascist governor of Rome Giangiacomo Calovini, member of the Chamber of Deputies of Italy Giangiacomo Feltrinelli (1926–1972), Italian publisher, businessman and political activist Giangiacomo di Gambarana (died 1538), Roman Catholic prelate, Bishop of Albenga Giangiacomo Guelfi (1924–2012), Italian operatic baritone Giangiacomo Magnani (born 1995), Italian professional footballer Giangiacomo Moretti (born 1843), Italian painter Giangiacomo Paleologo (1395–1445), Margrave of Montferrat Giangiacomo Teodoro Trivulzio (1597–1656), Italian Cardinal
See also Francesco Giangiacomo (1783–1864), Italian illustrator and engraver Giangiacomo Feltrinelli Editore, Italian publishing company founded in 1954