Guglielmo () is the Italian form of the masculine name William. It may refer to:
People with the given name Guglielmo:
Guglielmo I Gonzaga (1538–1587), Duke of Mantua and Montferrat Guglielmo Agnelli (c. 1238 – 1313), Italian sculptor and architect Guglielmo Arena (born 1973), Swiss football manager Guglielmo Bergamasco (c. 1485 – 1550), Italian architect Guglielmo Borremans (1670–1744), Baroque painter Guglielmo Bosca (born 1993), Italian alpine skier Guglielmo Caccia (1568–1625), Italian painter Guglielmo Achille Cavellini (1914–1990), influential Italian art collector and mail artist Guglielmo da Leoni (c. 1664 – 1740), Italian painter and engraver Guglielmo da Marsiglia (1475–1537), Italian painter of stained glass Guglielmo della Porta (c. 1500 – 1577), Italian architect and sculptor Guglielmo della Scala (died 1404), Lord of Verona Guglielmo Ebreo da Pesaro (c. 1420 – c. 1484), Italian dancing-master Guglielmo Embriaco (born c. 1040), Genoese merchant and military leader Guglielmo Ferrero (1871–1942), Italian historian, journalist and novelist Guglielmo Fiammingo (c. 1530 – 1587), sculptor Guglielmo Fieschi (13th century), Italian cardinal Guglielmo Gabetto (1916–1949), Italian former football (soccer) player Guglielmo il Giuggiola (16th century), Italian poet Guglielmo Letteri (1926–2006), Italian comic book artist Guglielmo Libri Carucci dalla Sommaja (1803–1869), Italian mathematician Guglielmo Marconi (1874–1937), Italian inventor Guglielmo Massaia (1809–1889), Italian Catholic missionary Guglielmo Nasi (1879–1971), Italian General Guglielmo Oberdan (1858–1882), Italian irredentist and terrorist Guglielmo Pallotta (1727–1795), Italian Roman Catholic Cardinal Willie Pep (1922–2006), real name Guglielmo Papaleo, American professional boxer Guglielmo Pepe (1783–1855), Italian general and patriot Guglielmo Plüschow (1852–1930), German photographer Guglielmo Quarenghi (1826–1882), Italian composer Guglielmo Sanfelice d'Acquavilla (1834–1897), cardinal of the Roman Catholic Church Guglielmo Scheibmeier (born 1924), Italian bobsledder Guglielmo Stendardo (born 1981), Italian football defender Guglielmo Verdirame, Baron Verdirame (born 1971), Italian-born British lawyer and member of the House of Lords Guglielmo Vicario (born 1996), Italian footballer Guglielmo Visconti (c. 1210 – 1276), Italian cardinal Mastro Guglielmo ( 12th century), Italian painter Niccolò Guglielmo Alforae, French engraver William Guglielmo Niederland (1904–1993), German-American psychoanalyst
People with the surname Guglielmo:
Augie Guglielmo (1915–1996), American baseball umpire Dudley A. Guglielmo (1909–2005), American insurance commissioner Tony Guglielmo (born 1940), American senator