Last name Октав (Octave 
, Octav 
, Oktav 
) , throughout the world, is quite a common family name. The cognomen Октав is habitual in Latin America and the Caribbean, particularly Saint Lucia, where it is a common surname, Guadeloupe, where it is quite a common surname, and Barbados, where it is quite a rare surname. Not in comparison with a country's population, it most frequently occurs in Indonesia, Ethiopia, and Turkey. Likewise, Октав is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Octave | France, Rwanda, Indonesia, Democratic Republic of the Congo, Ethiopia |
| Octav | Romania, Canada, France, United States, Indonesia |
| Oktav | Germany, Sweden, United States, Indonesia, Turkey |
| Октав | Russia, Ukraine |