| 4301 | WSRY | Winamac Southern Ry. Co. | 1/1994-7/2005 | | NAKINA |
| 4302 | WSRY | Winamac Southern Ry. Co. | 1/94-7/2000 | | NRHS |
| 4303 | WSRY | WINAMAC SOUTHERN RAILWAY CO. | | | PWRC |
| 4304 | WSRY | Winamac Southern Railway | | | RSRV |
| 4305 | WSRY | WINAMAC SOUTHERN RAILWAY COMPANY | | | SCAC4 |
| 4306 | WSRZ | WISCONSIN & SOUTHERN RAILROAD CO. | | | PWRC |
| 4307 | WSRZ | Wisconsin and Southern Railroad | | | RSRV |
| 4308 | WSS | Vilga-Aviaservice | Callsign: Vilga-Service, | KZ | AVCODES |
| 4309 | WSS | Winston-Salem Southbound Ry. Co. | 8/1920-7/2005 | | NAKINA |
| 4310 | WSS | Winston-Salem Southbound Ry. Co. | 4/38-7/2000 | | NRHS |
| 4311 | WSS | (CSXT) WINSTON-SALEM SOUTHBOUND RAILWAY CO. | | | PWRC |
| 4312 | WSS | Winston-Salem Southbound Railway | | | RSRV |
| 4313 | WSS | WINSTON-SALEM SOUTHBOUND RAILWAY CO | | | SCAC4 |
| 4314 | WSSC | WESTERN SALT COMPANY | | | SCAC4 |
| 4315 | WSSH | WALL STREET SYSTEMS OF OHIO LLC | | | SCAC4 |
| 4316 | WSSJ | WORLD SHIP SUPPLY SOUTHEAST LLC | | | SCAC4 |
| 4317 | WSSK | Rail Cargo Carrier – Slovakia s.r.o. | | SK | VKM |
| 4318 | WSSL | WESTERN STATES PETROLEUM INC | | | SCAC4 |
| 4319 | WSSM | WESTSIDE MOVING & STORAGE | | | SCAC4 |
| 4320 | WSSO | WISSOTA TRANSPORT LLC | | | SCAC4 |
| 4321 | WSSR | WESTSTAR | | | SCAC4 |
| 4322 | WSSU | WILHELMSEN SHIPS SERVICE GEORGIA LLC | | GE | BIC |
| 4323 | WSSX | Wedron Silica Co. | added 4/1986; 1/1994-7/2005 | | NAKINA |
| 4324 | WSSX | Wedron Silica Co. | added 4/86; 1/94-7/2000 | | NRHS |
| 4325 | WSSX | WEDRON SILICA CO. | | | PWRC |
| 4326 | WSSX | Wedron Silica | | | RSRV |
| 4327 | WSSX | WEDRON SILICA COMPANY | | | SCAC4 |
| 4328 | WSSY | WILLIN SPECIALIZED SERVICES INC | | | SCAC4 |
| 4329 | WST | Western Air Limited | IATA: WU, Callsign: Western Bahamas, | BS | AVCODES |
| 4330 | WST | Western Air | | | ICAO1 |
| 4331 | WST | WINSTON SALEM TERMINAL CO. | | | PWRC |
| 4332 | WST | Wagon Service Travel | | SK | TRAFFIC |
| 4333 | WSTA | WESTERN STAR TRANSPORTATION LLC | | | SCAC4 |
| 4334 | WSTBA | Westbahn Management GmbH | | AT | VKM |
| 4335 | WSTH | WEST HARTFORD MOVING & STORAGE CO. | | | SCAC1 |
| 4336 | WSTI | WESTTRANSAUTO INC | | | SCAC4 |
| 4337 | WSTK | WISE TRUCKING | | | SCAC4 |
| 4338 | WSTL | West Suburban Transit Lines | City: Chicago | USA | TRAFFIC |
| 4339 | WSTM | WESTERN MARINE TRANSPORT NV | | | SCAC4 |
| 4340 | WSTN | Wagonservice spol. sr.o. | | SK | VKM |
| 4341 | WSTO | WEST OIL CO INC | | | SCAC4 |
| 4342 | WSTP | WESTLAND TRANSPORTATION | | | SCAC4 |
| 4343 | WSTR | WILMOTH, SCOTT TRUCKING LLC | | | SCAC4 |
| 4344 | WSTS | WILDERNESS STABLES & TACK LTD | | | SCAC4 |
| 4345 | WSTT | Westchester Street Transportation | | US-NY | TRAFFIC |
| 4346 | WSTV | WESTERVELT TRANSPORT & SET-UP INC | | | SCAC4 |
| 4347 | WSTX | Whitestone Supply Co. | 7/2000-7/2005 (not listed) | | NAKINA |
| 4348 | WSTX | Whitestone Supply Co. | Jul-00 | | NRHS |
| 4349 | WSTX | WHITESTONE SUPPLY CO. | | | PWRC |
| 4350 | WSTX | Whitestone Supply | | | RSRV |
| 4351 | WSTZ | WESTSIDE TRANSPORT, INC. | | | PWRC |
| 4352 | WSTZ | Westside Transport | | | RSRV |
| 4353 | WSTZ | WESTSIDE TRANSPORT, INC. | | | SCAC4 |
| 4354 | WSUL | WHOLESALE UNIVERSAL DISTRIBUTORS IN | | | SCAC4 |
| 4355 | WSVT | WATKINS AND SHEPARD TRUCKING INC (T | | | SCAC4 |
| 4356 | WSVU | NV TRUCK EN TANKCLEANING TACK NV | | B | BIC |
| 4357 | WSW | Swoop, Inc | IATA: WO, Callsign: Swoop, IATA Prefix: 995, Ulta LCC subsidary of WestJet. Planned startup 20 June 2018 with Y189 B737-800. | CDN | AVCODES |
| 4358 | WSW | | | D | TRAFFIC |
| 4359 | WSWD | WHOLESALE WOOD PRODUCTS | | | SCAC4 |
| 4360 | WSWE | WESTERN SOLID WASTE | | | SCAC4 |
| 4361 | WSWI | WEST WISCONSIN TRANSPORT INC | | | SCAC4 |
| 4362 | WSWK | WISNIEWSKI TRUCKING CORP | | | SCAC4 |
| 4363 | WSWN | WESTWINN GROUP CORP | | | SCAC4 |
| 4364 | WSWO | WESTWOOD TRUCKING INC | | | SCAC4 |
| 4365 | WSWX | Wisconsin Steel Co. | 8/1920-4/1938 | | NAKINA |
| 4366 | WSWX | Wisconsin Steel Co. | Apr-38 | | NRHS |
| 4367 | WSWX | WISCONSIN STEEL CO. | | | PWRC |
| 4368 | WSX | Wessex Air Services Ltd. | Callsign: Wessex, | GB | AVCODES |
| 4369 | WSX | Eurojet Ltd. d/b/a Merlin | Callsign: Wessex, | GB | AVCODES |
| 4370 | WSX | Weirton Steel Co. | 8/1920-10/1957; eliminated 7/1959 | | NAKINA |
| 4371 | WSX | Weirton Steel Co. Division, National Steel Corp. | added 7/1959; 4/1961 | | NAKINA |
| 4372 | WSX | Weirton Steel Division, National Steel Corp. | 7/1965-10/1966 | | NAKINA |
| 4373 | WSX | Weirton Steel Co. Division, National Steel Corp. | eliminated 1/1967 | | NAKINA |
| 4374 | WSX | Weirton Steel Division, National Steel Corp. | added 1/1967; 4/1970-1/1980; eliminated 5/1983; 1/1994-7/2005 (not listed) | | NAKINA |
| 4375 | WSX | Weirton Steel Co. | 4/38-10/57; eliminated 7/59 | | NRHS |
| 4376 | WSX | Weirton Steel Co. Division, National Steel Corp. | added 7/59; 4/61 | | NRHS |
| 4377 | WSX | Weirton Steel Division, National Steel Corp. | 7/65-10/66 | | NRHS |
| 4378 | WSX | Weirton Steel Co. Division, National Steel Corp. | eliminated 1/67 | | NRHS |
| 4379 | WSX | Weirton Steel Division, National Steel Corp. | added 1/67; 4/70-1/80; eliminated 5/83; 1/94-7/2000 | | NRHS |
| 4380 | WSX | WEIRTON STEEL DIV., NATIONAL STEEL CORP. | | | PWRC |
| 4381 | WSX | National Steel Corporation Weirton Steel Division | | | RSRV |
| 4382 | WSXC | WILES TRANSPORT INC | | | SCAC4 |
| 4383 | WSXD | WESTERN EXPRESS (DEDICATED DIVISION | | | SCAC4 |
| 4384 | WSXE | WESTERN EXPRESS (EMERGENCY DIVISION | | | SCAC4 |
| 4385 | WSXF | WESTERN EXPRESS (FLATBED DIVISION) | | | SCAC4 |
| 4386 | WSXI | WESTERN EXPRESS INC | | | SCAC4 |
| 4387 | WSXL | WHITE STAR TRANSPORTATION LLC | | | SCAC4 |
| 4388 | WSXR | WESTCO EXPRESS INC | | | SCAC4 |
| 4389 | WSXT | WESTERN TRANSPORT LLC | | | SCAC4 |
| 4390 | WSXW | WILSONS TRANSIT | | | SCAC4 |
| 4391 | WSYL | WILLIAM SYSTEM LTD, THE | | | SCAC4 |
| 4392 | WSYP | White Sulphur Springs & Yellowstone Park Ry. Co. | 1/1975; eliminated 10/1975; 1/1980; eliminated 7/1980 | | NAKINA |
| 4393 | WSYP | White Sulphur Springs & Yellowstone Park Ry. Co. | 1/75-1/80; eliminated 7/80 | | NRHS |
| 4394 | WSYP | WHITE SULPHUR SPRINGS & YELLOWSTONE PARK RAILWAY | | | PWRC |
| 4395 | WSYP | White Sulphur Springs and Yellowstone Park Railway | | | RSRV |
| 4396 | WSYS | WR SYSTEMS | | | SCAC4 |
| 4397 | WSZ | WEDRON SILICA | | | PWRC |
| 4398 | WSZC | WALKERS SPECIALIZED CARRIERS INC | | | SCAC4 |
| 4399 | WSZI | WRIGHT SPECIALIZED INC | | | SCAC4 |
| 4400 | WT | Nigeria Airways Ltd. | ICAO: NGA, Callsign: Nigeria, IATA Prefix: 087, Ceased operations | WAN | AVCODES |
