| 1 | XR | SkyWest Airlines Pty. Ltd. | ICAO: OZW, Callsign: Ozwest, IATA Prefix: 608, Name changed to Virgin Australia Regional Airlines Pty Ltd. Designator XR reinstated by IATA | AUS | AVCODES |
| 2 | XR | Virgin Australia Regional Airlines Pty Ltd. | ICAO: OZW, Callsign: Ozwest, IATA Prefix: 608, Designator XR recalled by IATA. Name changed from SkyWest Airlines Pty. Ltd. Designator XR reinstated by IATA | AUS | AVCODES |
| 3 | XR | Touristic Aviation Services Ltd. t/a Corendon Airlines Europe | ICAO: CXI, Callsign: Touristic, IATA Prefix: 187, | M | AVCODES |
| 4 | XR | Xaver Riebel Gleislogistik GmbH | | DE | VKM |
| 5 | XRA | Intensive Air (Pty) Ltd. | IATA: IM, Callsign: Intensive, Ceased opertions on 09 April 2002. Designator IM* reinstated by IATA | ZA | AVCODES |
| 6 | XRA | Intensive Air | | | ICAO1 |
| 7 | XRAIL | Crossrail Benelux nv | | BE | VKM |
| 8 | XRAM | X-RAY MARITIME SA PANAMA | | | SCAC4 |
| 9 | XRAY | X-RAY SHIPPING SA PANAMA | | | SCAC4 |
| 10 | XRC | Express Air Cargo | IATA: 7A, IATA Prefix: 336, Setup by Logistic Express and UPS. AOC granted on 04 October 2016. | TN | AVCODES |
| 11 | XRFZ | CSX TRANSPORTATION, INC. | | | PWRC |
| 12 | XRFZ | CSX Transportation | | | RSRV |
| 13 | XRFZ | CSX TRANSPORTATION | | | SCAC4 |
| 14 | XRI | Crossrail Italia S.r.l | | IT | VKM |
| 15 | XRLC | XOTIC REPLICA LLC | | | SCAC4 |
| 16 | XRO | Exxaero BV | Callsign: Cramer, | NL | AVCODES |
| 17 | XRRU | (XTRZ) XTRA INTERMODAL | | | PWRC |
| 18 | XRRZ | (XTRZ) XTRA INTERMODAL | | | PWRC |
| 19 | XRTE | XRT EXPRESS REEFER TRANSPORT INC | | | SCAC4 |
