Across the world, Duílio (Duilio 
, Duílio 
) is a common masculine given name. The first name Duílio is characteristic of Italy, where it is quite a common masculine name, Argentina, where it is quite a rare masculine name, and Nicaragua. Not in comparison with a country's population, it is commonest in Italy, Argentina, and Brazil. Very seldom, Duílio is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Duilio | Nicaragua, Italy, Argentina, Brazil, Venezuela |
| Duílio | Portugal, Argentina, Brazil, United States |
|
duílio pedrosa Brazilian association football player (1931-2009), BR (b. 1931) |
|
| duílio genari Brazilian politician, BR (b. 1937) |
|
|
| duílio de castro faria Brazilian politician, BR (b. 1963) |
|
|
| duílio m z a silva researcher (ORCID 0000-0002-2610-2254) |
|
|
| duílio bernardi BR |
|
Melo, Novaes, Marques, Marçal, Miranda, Almeida, Andrade, Araújo, Barbosa, Batista, Pereira, Ribeiro, Júnior, Freitas, Malfatti, Sasdelli, Fernando, Ferreira, Oliveira, Anderlini, Cerqueira, Rodrigues, Júlio, Garcia, Borges, Castro, Saba, Cruz, Reis, Leal, Lima, Lobo, Neto, Silva, Souza, Alves, Fernandes, Costa, Brito, Paiva, Ramos, Dutra, Gomes, Lopes, Teles, Tunes, Filho, Santos, Braga, and Guimarães