The most common name in the United Kingdom (is perhaps unsurprisingly) Smith.
The Top 10 of most common names in the UK is:
1. Smith
2. Jones
3. Taylor
4. Williams
5. Brown
6. Davies
7. Evans
8. Wilson
9. Thomas
10. Roberts
According to The British Surnames Website, the third most common surname is "Harris". (see related link)
Smith
Williams
The most common South American surname in Argentina is Fernandez. In Brazil, the most common surname is Silva. In Chile, the most common surname is Gonzalez.
Garcia is the most common surname in Spain.
Garcia is the most common Spanish surname.
The most common surname in Greece is Papadopoulos.
Lithuania has different top ranked surnames for men and women. The most common male surname is Kazlauskas. The most common female surname is KazlauskienÄ—.
White
I think the most common lebanese surname would either be Khouri, Elkhouri or Georgeos
The surname Lacey is an English and Irish (of Norman origin) place name. The surname is widespread in Britain and Ireland, but most common in Nottinghamshire. In Ireland the family is associated particularly with County Limerick.
The most common surname in Newfoundland, Canada is Smith.