|Pronunciation||Spanish: [ˈdiaθ], in Latin America: [ˈdias]|
|Meaning||"Son of Diego"|
|Region of origin||Spain, Portugal|
|Related names||Diaz (anglicized), Dias (English translation)|
Díaz is a common Spanish and Portuguese surname with multiple meanings. First found in Castile, where the name originated in Visigoths period. The name accounts for ~0.74% of the Spanish population, ranking 14th most frequently found surname in both 1999 and 2004 (Mateos & Tucker 2008, OcioTotal 1999). Compared to the most popular Spanish surname of those years.
There is minor evidence that Díez may be equivalent to Diaz, in the form of Spanish language listing of most frequent surnames in 1999 Spain (OcioTotal 1999). However, a 2008 in-press academic manuscript about Spanish naming in 2004 suggests otherwise, listing statistics for "Diaz" and "Diez" separately (Mateos & Tucker 2008).
In relation to descent from the Biblical names James and Jacob, it has been surmised that Diaz is a derivation of Diego from Iago (Smith 1986), Sant Iagus. A second source suggests Díaz as being derived from a Gothic form of the paternal genitive of Dia, as in "Dia's child", or Diag, Diago or Diego (Dixon 1857). Dias translates into Son of Jacob
The surname is cognate with the Portuguese language surname Dias.
Díaz and the anglicized form Diaz appear to be surnames only, without evidence for use as given names. Use of Díaz may arise through Anglicization of Portuguese language Dias, as in the case of Bartolomeu Dias.
Many examples of the surnames Díaz exist among historically notable people as a patronymic of Diego. Among the earliest such examples is El Cid, whose real name as Rodrigo Díaz de Vivar, and whose father's given name was Diego (Catholic Encyclopedia 1913).
There is at least one instance of use as a single name, the former Norwegian rap artist Diaz, who was born to a Spanish father and Norwegian mother; his birth name was "Andrés Rafael Díaz".
In Latin America Díaz was among the top 25% of surnames in use based on a study conducted in 1987 by the Institute for Genealogy and History for Latin America (De Platt 1996, pages 31–32).
Spanish surnames, including Díaz, are found more abundantly in Southern Italy than other non-Italian surnames as a result of the domination of Italy by Spain during the 17th century (Fucilla 1949).
The following matrix contains available information on the frequency of this surname in various countries across a span of years.
|Australia||2002: 0.008% (rank ?)(c)|
|New Zealand||2002: 0.002% (rank ?)(c)|
|Spain||1999: 0.74% (rank 14)(a)||2004: na% (rank 14)(b)|
|United Kingdom||1881: na% (rank 23,037)(c)||1998: 0.001% (rank 10,773)(c)|
|United States||1964: 0.047% (rank 335)||1990: 0.084% (rank 99)(d)
1990: 0.014% (rank ?)(c)
|2000: 0.18% (rank 73)(d)|
Reference codes, see #References: (a)=OcioTotal 1999, (b)=Mateos & Tucker 2008, (c)=Longley, et al., (d)=United States Census Bureau 1995, (e)=United States Census Bureau 2000
Notable people sharing the surname 
Owing to the common nature of this surname, there are many notable people who share it. Among the most notable of these are:
- El Cid (11th century), born Rodrigo Díaz, conqueror and subsequent ruler of Valencia, Spain
- Bartholomew Diaz (15th century), the anglicized form of the name, who was the first European known to have sailed around the Southern tip of Africa
- Bernal Díaz del Castillo (16th century), who provided an eye witness narrative for the destruction of the Aztec Empire by Spanish conquistadors
- José E. Díaz (19th century), hero of the Paraguayan War and appearing on the 100 Paraguayan guaraní coin
- Porfirio Díaz (19th century), President of Mexico following the French intervention in Mexico
- Armando Diaz (20th century), Italian Supreme Commander during World War I
- Paquito Diaz (20th century), veteran Filipino actor and brother of Romy
- Romy Diaz (20th century), veteran Filipino actor and brother of Paquito
- Gloria Diaz (20th century), the first Filipino to bring home the Miss Universe crown.
- Joe Diaz (20thCentury), One of first Mexican-Americans to attend University of California at Davis and Berkeley; Officer in the USMC WWII; Executive, Shell Chemical Co.
- Matthew Diaz (20th century), American military lawyer responsible for the release of the identities of detainees at the Guantanamo Bay detention camp to the Center for Constitutional Rights
- Charley L. Diaz (21st Century) U.S. Coast Guard Captain who led the largest maritime drug bust in U.S. history.
- Cameron Diaz (born 1972), American actress
- Diaz (musician) (born 1976 as "Andres Rafael Diaz Rosa"), a rapper from Jessheim, Norway
- Nick Diaz (21st century), mixed martial arts (MMA) fighter, brother of Nate
- Nate Diaz (21st century), mixed martial arts (MMA) fighter, brother of Nick
- Oliver E. Diaz, Jr. (21st century), Justice, Mississippi Supreme Court
- Junot Díaz (21st century), Dominican-American writer who received the Pulitzer Prize for Fiction in 2008
- Raquel Diaz (born 1990), ring name of American professional wrestler Shaul Guerrero
- Raquel Roxanne Diaz, television personality and the host of 106 and Park on BET
- Jonny Diaz, American contemporary Christian musician originally from Lakeland, Florida
- Alyssa Diaz (21st century), Actress
- Patricia Díaz Perea, professional triathlete
See also 
- Rank 16 among Hispanic-Americans (De Platt 1996, pages 15–16)
- Bowie, Neil; G W L Jackson (2003-02-18). Surnames in Scotland over the last 140 years. General Register Office for Scotland. Retrieved 2008-05-01.
- Carr, Derek C. (March 1999) . "Arabic and Hebrew auctoritates in the Works of Enrique de Villena". In Auguste Elfriede Christa Canitz and Gernot Rudolf Wieland. From Arabye to Engelond. University of Ottawa Press. pp. 56–57 (Note 16). ISBN 0-7766-0517-8. Retrieved 2008-05-01.
- Catholic Encyclopedia (1913). s:Catholic Encyclopedia (1913)/El Cid. Retrieved on 2008-05-02.
- De Platt, Lyman (1996) . Hispanic Surnames and Family History. The Hispanic Book of Generations 1 (1st ed.). Genealogical Publishing Com. ISBN 0-8063-1480-X. Retrieved 2008-04-30.
- Dixon, Bernard Homer (2006-08-08) . Surnames (2nd ed.). Google Books. p. 20. Retrieved 2998-04-30.
- Fucilla, Joseph Guerin (1987) . Our Italian Surnames (reprint ed.). Genealogical Publishing Com. pp. 109, footnote 6. ISBN 0-8063-1187-8. Retrieved 2008-04-30.
- Mateos, Pablo; Ken Tucker (2008). "Forenames and Surnames in Spain in 2004" (PDF). Names a Journal of Onomastics. (in press). Retrieved 2008-04-28.
- OcioTotal (1999-12-01). "Los 40 apellidos mas comunes en España". Genealogía y heráldica (in Spanish). OcioTotal.com. Retrieved 2008-04-28.
- Smith, Elsdon Coles (1986) . "Surnames From Father's Name". American Surnames. Genealogical Publishing Com. pp. 63–64. ISBN 0-8063-1150-9. Retrieved 2008-04-27.
- United States Census Bureau (9 May 1995). s:1990 Census Name Files dist.all.last (1-100). Retrieved on 2008-04-04.
- United States Census Bureau (2000). "Top 1000 Names" (XLS). Frequently Occurring Surnames From Census 2000. U.S. Department of Commerce. Retrieved 2008-05-01.[dead link]
- A history of the Díaz surname compiled by the Institute for Genealogy and History for Latin America is available for a fee. See pages 38 and 39 of http://books.google.com/books?id=xxcSboo5KTAC for more information.