Guglielmo
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Meaning
Italian form of William ("will helmet"); famously borne by Guglielmo Marconi, inventor of practical radio transmission
The story
Guglielmo is William in full Italian dress, the same Germanic name built from will and helmet, unrolled across four syllables. It sits in the history books because of Guglielmo Marconi, the Bologna-born inventor who gathered the era's scattered discoveries about electromagnetic waves and engineered them into practical radio, sending a wireless signal across the Atlantic in 1901 and sharing the Nobel Prize in Physics in 1909; within a decade, ships at sea, including the one that raced to the Titanic's survivors, depended on Marconi equipment. For all that fame, the first name never crossed the ocean with it: Guglielmo has stayed a true rarity in American records, showing its first faint presence only in the most recent decade. That leaves it a bold, nearly untouched choice, operatic in sound and anchored to the man who taught the world to broadcast.
How popular is Guglielmo around the world?
Guglielmo does not appear in US Social Security baby-name records, which list only names given to at least five babies in a year. There is no popularity curve to chart: a genuinely rare pick. In Spain, 67 residents are named Guglielmo, ranked 11,393rd among men, with a mean age of 49.2 years.
Guglielmo is on the official records of Spain and Brazil.
United States
under 5 a year
Guglielmo does not appear in US Social Security baby-name records, which list only names given to at least five babies in a year. There is no popularity curve to chart: a genuinely rare pick.
Births with a Social Security record. Source: U.S. Social Security Administration
Spain
1 in 670,000
In Spain, 67 residents are named Guglielmo, ranked 11,393rd among men, with a mean age of 49.2 years.
Residents of Spain on 1 January 2025. Spain publishes how old a name’s living bearers are, not a birth series, so there is no year chart. Source: INE (Spain), Censo de Población anual, 1 January 2025
Brazil
At the 2022 census, 64 people in Brazil were named Guglielmo, ranked 56,233rd, with a median age of 46.
People alive and resident in Brazil at the 2022 census, a living-population count, not births; names under 20 are withheld at source. Source: IBGE, Censo Demográfico 2022
England and Wales
last on record 2012
Guglielmo is not on the 2025 record for England and Wales, where spellings under 3 in a year are withheld at source.
The count never rose above 3 in a year, too few to chart.
Birth registrations in England and Wales (not the whole UK); exact spellings are counted separately, and any spelling under 3 in a year is withheld at source. Source: Office for National Statistics, baby names in England and Wales
Montevideo City
last on record 1966
Guglielmo is not on the 2011 record for Montevideo, whose registry withholds nothing, so the spelling was not given there that year.
The count never rose above 1 in a year, too few to chart.
Births in the department of Montevideo (not all of Uruguay) by first name and year of birth, 1940–2011, from the city’s civil registry, which writes names in capitals, almost always without accents; counted as spelling groups (accent and punctuation variants merged), nothing is withheld at source, and 2012 is excluded as a partial year. Source: Servicio de Registro Civil, Intendencia de Montevideo, Partidas de Registro Civil de Montevideo (Licencia de Datos Abiertos - Uruguay); 2012 dropped as partial
South Australia
last on record 1972
Guglielmo is not on the 2017 record for South Australia, whose registry publishes every name given that year.
The count never rose above 2 in a year, too few to chart.
Births registered in South Australia (not all of Australia) by first name and year of registration, 1944–2017, from the state’s Births, Deaths and Marriages registry, which publishes every name down to a single birth in capitals; a spelling its export repeats inside a year is counted once, and from 2018 only a top 100 is published, so the series ends at 2017. Source: Consumer and Business Services (South Australia), popular baby names
Not on the record in Mexico City, Argentina, Puerto Rico, Canada, Ireland, New Zealand, Scotland and Poland: those registries withhold small counts, so rare uses may sit below their floors.
Not on the Chile record: nametree keeps spellings that reached 5 registrations in some year, so rarer uses are not shown. Not on the France record: nametree keeps spellings that reached 20 births in some year, so rarer uses are not shown. Not on the Austria record for 1984 to 2025: Statistik Austria publishes every first name down to a single birth, so this name was not given there in those years (before 2010 the record covers babies with Austrian citizenship only). Not on Norway’s list: Statistics Norway lists only first names carried by 200 or more living people, so rarer names are not shown.
Keep exploring
The Guglielmo deep dive
Whether you’re naming a baby or exploring your own name’s history, this is a personal letter, not a list: where Guglielmo truly comes from, how it traveled, and what a century of records reveals. If you have grown a tree on nametree, it also considers how Guglielmo fits with your family’s names and surname.
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