Family name Сидни (Sidney 
, Sydney , Sidni 
) , throughout the world, is a common cognomen. The surname Сидни is habitual in Saint Lucia, where it is quite a common surname, Jersey, and Cabo Verde (explore the name in all countries). In absolute terms, it most frequently occurs in the United States, Nigeria, and Australia. More frequently, Сидни is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Sidney, Sydney | Zambia, Democratic Republic of the Congo, United States, South Africa, Brazil |
| Sidni | Nigeria, Philippines, Canada, United States, Brazil |
| Сидни | Russia, Lithuania |