Last name Sigu (Sieglinde 
, Siegmund 
, Sigu 
) , globally, is a common cognomen. The cognomen Sigu is characteristic of Germany, where it is quite a rare surname, Austria, and Malta. Not in comparison with a country's population, the name is most common in Germany, the United States, and Ethiopia. More frequently, Sigu is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Sieglinde | Italy, Austria, United States, China, Germany |
| Siegmund | Czechia, Poland, Austria, United States, Germany |
| Sigu | India, Ethiopia, United States, Kenya, Germany |
| 水牛 | China |