| 1 | WK | American Falcon, S.A. | ICAO: AFB, Callsign: American Falcon, IATA Prefix: 676, | RA | AVCODES |
| 2 | WK | Greenair | ICAO: GRN, | TR | AVCODES |
| 3 | WK | Westküstenflug | ICAO: WKF, | D | AVCODES |
| 4 | WK | Western Alaska Airlines, Inc. | Callsign: Western Alaska, | USA | AVCODES |
| 5 | WK | Edelweiss Air AG | ICAO: EDW, Callsign: Edelweiss, IATA Prefix: 945, IATA Designator changed from 8R*. IATA desigantor changed 1I, then from 5H* | CH | AVCODES |
| 6 | WKAF | WILL TRUCK | | | SCAC4 |
| 7 | WKAG | Weiacher Kies AG | | CH | TRAFFIC |
| 8 | WKAG | Weiacher Kies AG | | CH | VKM |
| 9 | WKAL | WEAVER, K L TRUCKING | | | SCAC4 |
| 10 | WKAY | WESKAY LLC | | | SCAC4 |
| 11 | WKB | Wittlager Kreisbahn | | D | TRAFFIC |
| 12 | WKC | Western Kenya Aircharters Co. Ltd. | Callsign: Mushroom, | EAK | AVCODES |
| 13 | WKCI | WASATCH TANK LINES LLC | | | SCAC4 |
| 14 | WKCT | WOODS, KC TRUCKING INC | | | SCAC4 |
| 15 | WKCY | WAKE & CO INC | | | SCAC4 |
| 16 | WKD | Warszawska Kolej Dojazdowa | | PL | TRAFFIC |
| 17 | WKD | Warszawska Kolej Dojazdowa sp. z o.o. | | PL | VKM |
| 18 | WKDC | WILKINS DRAYING CO | | | SCAC1 |
| 19 | WKDC | WEST-K TRUCKING | | | SCAC4 |
| 20 | WKDL | WHITAKER LAND & LIVESTOCK INC | | | SCAC4 |
| 21 | WKDR | WICKS, DEREK | | | SCAC4 |
| 22 | WKDS | WALKER TEMPLE LOGISTICS GROUP LLC | | | SCAC4 |
| 23 | WKEB | WINKLE OIL CO INC | | | SCAC4 |
| 24 | WKEC | WHITAKER TRANSPORTATION COMPANY INC | | | SCAC4 |
| 25 | WKEE | WARNER, KURT ENTERPRISES LLC | | | SCAC4 |
| 26 | WKEH | WINKELS, LUKE | | | SCAC4 |
| 27 | WKEI | WILKES TRANSPORT, INC | | | SCAC1 |
| 28 | WKEL | WINKEL DISTRIBUTING COMPANY | | | SCAC4 |
| 29 | WKES | WICKER SERVICES, INC | | | SCAC1 |
| 30 | WKES | WICKER SERVICES INC | | | SCAC4 |
| 31 | WKF | Westküstenflug | IATA: WK, | D | AVCODES |
| 32 | WKFD | WAKEFIELD OIL CO INC | | | SCAC4 |
| 33 | WKFT | WKF TRANSPORT INC | | | SCAC4 |
| 34 | WKGE | WORKING ENVIRONMENTS | | | SCAC4 |
| 35 | WKGN | WEISS, KURT GREENHOUSES INC | | | SCAC4 |
| 36 | WKH | Kharkov Aircraft Manufacturing Company | Callsign: West-Kharkov, | UA | AVCODES |
| 37 | WKH | Kharkov Aircraft Manufacturing Company | | | ICAO1 |
| 38 | WKHA | Wilhelm Kemming GmbH | | DE | VKM |
| 39 | WKHI | W K HEAVY HAUL INC | | | SCAC4 |
| 40 | WKHX | Rail Connection, Inc. | added 10/2003; 7/2005 | | NAKINA |
| 41 | WKHX | RAIL CONNECTION, INC. | | | PWRC |
| 42 | WKHX | RAIL CONNECTION INC | | | SCAC4 |
| 43 | WKIF | WILK INC | | | SCAC4 |
| 44 | WKIL | WICKENS INDUSTRIAL LIMITED | | | SCAC4 |
| 45 | WKIZ | WYCOFF INDUSTRIES | | | PWRC |
| 46 | WKJM | WAKE, JIM TRUCKING | | | SCAC4 |
| 47 | WKJS | WALLNYK JOINT SERVICE STOCKHOLM | | | SCAC4 |
| 48 | WKJT | WALKER'S, JIM, TRANSFER CO | | | SCAC1 |
| 49 | WKKT | WALKER, KENNETH TRUCKING INC | | | SCAC4 |
| 50 | WKLB | WHITAKER ENTERPRISE CONTRACTOR LLC | | | SCAC4 |
| 51 | WKLI | WHITE KNIGHT LIMOUSINE INC | | | SCAC4 |
| 52 | WKLL | WALKER, L E TRANSPORT LTD | | | SCAC4 |
| 53 | WKLR | WESTERN KENTUCKY RAILWAY, LLC | | | PWRC |
| 54 | WKLS | WALKER LOGISTICS INC | | | SCAC4 |
| 55 | WKLY | WEEKLEYS TRUCKING CO LLC | | | SCAC4 |
| 56 | WKM | West Kent Motor Services | | GB | TRAFFIC |
| 57 | WKMN | WINKELMOLEN NURSERY LTD | | | SCAC4 |
| 58 | WKMP | WHITE OAK MOUNTAIN TRANSPORTATION | | | SCAC4 |
| 59 | WKMR | WEEKS MARINE INC | | | SCAC4 |
| 60 | WKMT | WAUKA MOUNTAIN TANKER SERVICE INC | | | SCAC4 |
| 61 | WKMW | WAH KWONG MARITIME AGENCY COMPANY L | | | SCAC4 |
| 62 | WKN | WESTMONTAGE Kabel und Netzwerk GmbH | | DE | VKM |
| 63 | WKNB | WILKINS BUS LINES INC | | | SCAC4 |
| 64 | WKNG | WATKINS TRUCKING CO INC | | | SCAC4 |
| 65 | WKNO | WATKINS OIL CO INC | | | SCAC4 |
| 66 | WKNP | W K TRANSPORT | | | SCAC4 |
| 67 | WKNT | WESTON, KEVIN TRUCKING | | | SCAC4 |
| 68 | WKOC | WILKINSON OIL COMPANY INC | | | SCAC4 |
| 69 | WKOL | WATKINS OIL COMPANY INCORPORATED | | | SCAC4 |
| 70 | WKOX | Western Oil Corp. | 7/1923 | | NAKINA |
| 71 | WKOX | WESTERN OIL CORP. | | | PWRC |
| 72 | WKPR | WHITTAKER, PATTERSON ARCHITECTURAL | | | SCAC4 |
| 73 | WKPS | WICKS PIES INC | | | SCAC4 |
| 74 | WKPT | WALKER, PAT TRUCKING LLC | | | SCAC4 |
| 75 | WKPX | Wood Chemical Products Co. | 7/1930 | | NAKINA |
| 76 | WKPX | Southern Pine Chemical Co. | 7/1935-7/1937 | | NAKINA |
| 77 | WKPX | SOUTHERN PINE CHEMICAL CO. [WOOD CHEMICAL PRODUCTS CO.] | | | PWRC |
| 78 | WKQC | WILKES EQUIPMENT CO INC | | | SCAC4 |
| 79 | WKRD | WALKER, DERRICK RACING INC | | | SCAC4 |
| 80 | WKRF | WALKER FUELS | | | SCAC4 |
| 81 | WKRG | WALKER GROUP INC, THE | | | SCAC4 |
| 82 | WKRL | Western Kentucky Ry., L.L.C. | added 4/1995; 7/2000; eliminated 7/2003; 7/2005 | | NAKINA |
| 83 | WKRL | Western Kentucky Ry., L.L.C. | added 4/95; 7/2000 | | NRHS |
| 84 | WKRL | WESTERN KENTUCKY RAILWAY, LLC | | | PWRC |
| 85 | WKRL | Western Kentucky Railway | | | RSRV |
| 86 | WKRL | WESTERN KENTUCKY RAILWAY LLC | | | SCAC4 |
| 87 | WKRM | WARKENTIN, ROBERT & MARILYN | | | SCAC4 |
| 88 | WKRO | WALKER OIL CO | | | SCAC4 |
| 89 | WKS | WANAMAKER KEMPTON & SOUTHERN | | | PWRC |
| 90 | WKSH | WATKINS AND SHEPARD TRUCKING, INC | | | SCAC1 |
| 91 | WKSH | WATKINS AND SHEPARD TRUCKING | | | SCAC4 |
| 92 | WKSI | WHILLOCK, K SERVICES INC | | | SCAC4 |
| 93 | WKT | Wojewodzka Kolumna Transportu Sanitarnego | Callsign: Woktrans, | PL | AVCODES |
| 94 | WKT | Diamond Executive Aviation Ltd. | Callsign: White Knight, Name changed to DEA Aviation Ltd. w.e.f. 22 December 2017. | GB | AVCODES |
| 95 | WKT | DEA Aviation Ltd. | Callsign: White Knight, Name changed from Diamond Executive Aviation Ltd. | GB | AVCODES |
| 96 | WKTB | WILKINS TRUCKING INC | | | SCAC4 |
| 97 | WKTE | WISE, KEITH TRUCK LINES INC | | | SCAC4 |
| 98 | WKTK | WALKER TRUCKING | | | SCAC4 |
| 99 | WKTO | WILKINS, KINDOLL TRUCKING | | | SCAC4 |
| 100 | WKTV | WHEEL KING TRANSHAUL INC | | | SCAC4 |
