Kotlyar, Kotliar, Kotlar, Cotlar, Cotlear, or Cotliar is an occupational surname, meaning "boilermaker" in multiple languages.
| Language | Masculine | Feminine |
|---|---|---|
| Belarusian (Romanization) | Катляр (Katlyar, Katliar) | |
| Czech | Kotlář | Kotlářová |
| Polish | Kotlarz | |
| Russian (Romanization) | Котляр (Kotlyar, Kotliar) | |
| Serbo-Croatian | Kotlar | |
| Slovak | Kotlár | Kotlárová |
| Ukrainian (Romanization) | Котляр (Kotlyar, Kotliar) | |
| Other | Cotlar, Cotliar, Cotlear |