Surname Костелецкий (Костелецкий 
, Kosteletzky 
, Kostelecky 
) , throughout the world, is quite a rare cognomen. The surname Костелецкий is characteristic of Czechia, where it is quite a rare surname, Belarus, and Austria. In absolute terms, it is the most numerous in the United States, Czechia, and Belarus.
| VARIANT | COUNTRY |
|---|---|
| Костелецкий | Belarus, Russia, Kazakhstan |
| Kosteletzky | Austria, Germany, Spain |
| Kostelecky | Czechia, Germany, Canada, United States, Austria |
| Kostelecký | Czechia |