| 1 | XW | China Xinhua Airlines | ICAO: CXH, Callsign: Xinhua, IATA Prefix: 779, Merged with Shanxi Airlines and Chang An Airlines to form Grand China Air, a subsidiary of Hainan Airlines on 29 November 2007. | PRC | AVCODES |
| 2 | XW | Orbit Express Airlines Hava Yollair A.s. (Orex) | ICAO: ORX, Callsign: Orex, Ceased operations | TR | AVCODES |
| 3 | XW | Sky Express | ICAO: SXR, Callsign: Skystorm, IATA Prefix: 492, Founded in 2006. Commenced operations on 29 January 2007. Ceased operations on 29 October 2011. Designator XW reinstated by IATA | RUS | AVCODES |
| 4 | XW | Pete Air Co., Ltd. | ICAO: NCT, Callsign: Pete Air, Name changed to Nokscoot | T | AVCODES |
| 5 | XW | NokScoot Airlines Company Limited | ICAO: NCT, Callsign: Big Bird, IATA Prefix: 478, Founded on 20 August 2014. Commenced operations on 20 May 2015. Ceased operations on 26 June 2020. NokScoot is a joint venture of Thailand's Nok Air and Singapore based Scoot. | T | AVCODES |
| 6 | XWEC | X WEST CARRIERS INC | | | SCAC4 |
| 7 | XWMA | WASHINGTON METROPOLITAN AREA TRANSIT AUTHORITY | | | PWRC |
| 8 | XWS | WSI Corporation | | USA | AVCODES |
| 9 | XWS | WSI Corporation | | | ICAO1 |
| 10 | XWW | World Weatherwatch | | CDN | AVCODES |
| 11 | XWW | World Weatherwatch | | | ICAO1 |
