Guglielmo () is the Italians, Italian form of the masculine name William (name), William. It may refer to:
People with the given name Guglielmo:
* Guglielmo I Gonzaga (1538–1587), Duke of Mantua and Montferrat
* Guglielmo Achille Cavellini (1914–1990), influential Italian art collector and mail artist
* Guglielmo Agnelli (c. 1238 – 1313), Italian sculptor and architect
* Guglielmo Bergamesco (16th century), Italian architect
* Guglielmo Borremans (born 1672), Baroque painter
* Guglielmo Caccia (1568–1625), Italian painter
* 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 (15th century), 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
* 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 (21st century), Italian bobsledder
* Guglielmo Stendardo (born 1981), Italian football defender
* Guglielmo Verdirame (21st century), Italian lawyer
* Guglielmo Vicario (born 1996), Italian footballer
* Guglielmo Visconti (c. 1210 – 1276), Italian cardinal
* Niccolo Guglielmo Alforae, French engraver
* William Guglielmo Niederland (1904–1993), German-American psychoanalyst
People with the surname Guglielmo:
* Dudley A. Guglielmo (1909–2005), Louisiana insurance commissioner
* Mark Guglielmo (born 1968), American murderer
{{given name, type=both
Italian masculine given names
Surnames from given names
