Klas or KLAS may refer to:
- Klas (restaurant), a Czech restaurant in Cicero, Illinois, which operated from 1922 to 2016
- KLAS-TV, a television station (channel 8) licensed to Las Vegas, Nevada, United States
- The ICAO airport code for Harry Reid International Airport, in Las Vegas, Nevada, United States
- Kumon Leysin Academy of Switzerland, a private high school in Leysin, Switzerland
- Claes, a given name in Scandinavia
- Eri Klas (1939–2016), Estonian conductor