| 101 | YB | South African Express Airways (Pty) Ltd. | ICAO: EXY, Callsign: Expressways, Designator YB recalled by IATA. Designator YB reinstated by IATA | ZA | AVCODES |
| 102 | YB | First European Airways | IATA: 5Y, | GR | AVCODES |
| 103 | YB | Harbour Air Ltd. | Designator H3 recalled by IATA | CDN | AVCODES |
| 104 | YB | Bora Jet Havacilik Tasimacilik Ucak | ICAO: BRJ, Callsign: Bora Jet, Commenced operations on 08 May 2010. Suspended operations on 24 April 2017. IATA designator changed from BJ* | TR | AVCODES |
| 105 | YB | The Youngstown Belt R.R. Co. | added 4/1997; 7/2000-7/2005 | | NAKINA |
| 106 | YB | The Youngstown Belt R.R. Co. | added 4/97; 7/2000 | | NRHS |
| 107 | YB | YOUNGSTOWN BELT RAILROAD CO. | | | PWRC |
| 108 | YB | Youngstown Belt Railroad | | | RSRV |
| 109 | YB | YOUNGSTOWN BELT RAILROAD COMPANY, T | | | SCAC4 |
| 110 | YBAR | YBARRA Y CIA SUDAMERICA S A | | | SCAC4 |
| 111 | YBCI | YOL BULK CARRIERS INC | | | SCAC4 |
| 112 | YBE | Stewart Aviation Services, Inc. | Callsign: Yellow Bird, | USA | AVCODES |
| 113 | YBE | Stewart Aviation Services | | | ICAO1 |
| 114 | YBFU | YELLOWBOX FIREWORKS, LLC | | USA | BIC |
| 115 | YBGH | YARBROUGH TRUCKING INC | | | SCAC4 |
| 116 | YBHA | YUBA HEAT | | | PWRC |
| 117 | YBLT | YERBA BUENA LTD | | | SCAC4 |
| 118 | YBRI | YELLOW BRICK ROAD LOGISTICS INC | | | SCAC4 |
| 119 | YBRL | YOUNG BROTHERS LIMITED | | | SCAC4 |
| 120 | YBSI | YELLOW BUS SERVICE INC | | | SCAC4 |
| 121 | YBST | YBS TRUCKING INC | | | SCAC4 |
| 122 | YBTI | YOUNG BROS TRUCKING INCORPORATED | | | SCAC4 |
| 123 | YBTL | YOUNGBLOOD TRUCK LINES INC | | | PWRC |
| 124 | YC | Trygg-Flyg Erik Trygg AB | ICAO: TYG, Callsign: Trygg, Designator YC recalled by IATA | S | AVCODES |
| 125 | YC | Flight West Airlines Pty Ltd. | ICAO: FWQ, Designator YC recalled by IATA | AUS | AVCODES |
| 126 | YC | Caverton Helicopters Ltd. | | WAN | AVCODES |
| 127 | YC | Yamal Airlines | ICAO: LLM, Callsign: Yamal, IATA Prefix: 664, Designator YL recalled by IATA. Designator YL reinstated by IATA | RUS | AVCODES |
| 128 | YCA | YELLOW CAB COMPANY | | | SCAC4 |
| 129 | YCBC | YELLOW CAB COMPANY | | | SCAC4 |
| 130 | YCCR | YANKEE CARTING CORP | | | SCAC4 |
| 131 | YCCU | DALIAN ZIQI CONTAINER MANUFACTURING CO., LTD. | | PRC | BIC |
| 132 | YCDA | YELLOW CAB | | | SCAC4 |
| 133 | YCEU | INTER-CONTINENTAL EQUIPMENT, INC. | | | PWRC |
| 134 | YCEU | Inter-Continental Equipment | | | RSRV |
| 135 | YCIN | YOCUM OIL COMPANY INC | | | SCAC4 |
| 136 | YCLB | YOURFREIGHTRATE.COM LLC | | | SCAC4 |
| 137 | YCLW | YUSHIP CO LTD | | | SCAC4 |
| 138 | YCMZ | YELLOW CREEK MINE | | | PWRC |
| 139 | YCOI | YODER & CO INC | | | SCAC4 |
| 140 | YCPU | JIANGSU YANCHENG PORT CONTAINER GROUP CO.,LTD | | PRC | BIC |
| 141 | YCR | YCR CORP | | | SCAC4 |
| 142 | YCSN | YO COUSIN | | | SCAC4 |
| 143 | YCTB | Yokohama City Transportation Bureau | City: Yokohama | J | TRAFFIC |
| 144 | YCTC | YC TRANSPORTATION INC | | | SCAC4 |
| 145 | YD | State Enterprise Gomelavia | ICAO: GOM, Callsign: Gomel, Name changed to Republican Aviation Unitary Enterprise | BY | AVCODES |
| 146 | YD | Synergy Aviation Ltd. | ICAO: SYG, Callsign: Synergy, IATA Prefix: 259, | GB | AVCODES |
| 147 | YD | Air Taxi Klagenfurt t/a Transalp Air | | A | AVCODES |
| 148 | YDC | YANKEE DOT CORP. | | | PWRC |
| 149 | YDC | Yankeetown Docks Corporation | | USA | TRAFFIC |
| 150 | YDCS | YAZICI DEMIR CELIK SANAYI VE TURIZM | | | SCAC4 |
| 151 | YDCX | Yankeetown Dock Corp. | added 7/1979; 1/1980; eliminated 1/1980 | | NAKINA |
| 152 | YDCX | Peabody Coalsales Co. | added 7/2005; 7/2005 | | NAKINA |
| 153 | YDCX | Yankeetown Dock Corp. | added 7/79; 1/80; eliminated 1/80 | | NRHS |
| 154 | YDCX | *YANKEETOWN DOCK CORP. | | | PWRC |
| 155 | YDCX | +PEABODY COALSALES CO. | | | PWRC |
| 156 | YDCX | PEABODY COALSALES COMPANY | | | SCAC4 |
| 157 | YDHR | York Durham Heritage Railway | | | RSRV |
| 158 | YDHR | York-Durham Heritage Railway | | CDN | TRAFFIC |
| 159 | YDIS | YANEZ, DIMAS | | | SCAC4 |
| 160 | YDKY | YACUCHA, DEAN KELLY | | | SCAC4 |
| 161 | YDLA | YARDA LUPITA | | | SCAC4 |
| 162 | YDLC | YVES DELORME INC | | | SCAC4 |
| 163 | YDRJ | YODER, JOSEPH | | | SCAC4 |
| 164 | YDRT | YODER TRUCKING | | | SCAC4 |
| 165 | YDSI | YESTERDAY DELIVERY SERVICE INC | | | SCAC4 |
| 166 | YDTI | YODER TRANSPORTATION INC | | | SCAC4 |
| 167 | YDTK | YELLOW DOG TRUCKING LTD | | | SCAC4 |
| 168 | YDWH | YOUNG, D W HAULAGE INC | | | SCAC4 |
| 169 | YDXU | PT INDONESIA GUANG CHING NICKEL AND STAINLESS STEEL IND | | RI | BIC |
| 170 | YE | Ilam Airline | ICAO: IRY, Callsign: Ilam, Name changed from Eram Airlines | IR | AVCODES |
| 171 | YE | Yanda Airlines | Designator XN recalled by IATA. Designator changed from ST*. Formerly Singleton Air Serivces | AUS | AVCODES |
| 172 | YE | Aryan Cargo & Express Logistics (P) Ltd. (ACE) | ICAO: ACQ, Callsign: Ace Cargo, IATA Prefix: 185, Ceased operations on 01 June 2010. | IND | AVCODES |
| 173 | YE | Yan Air Ltd. | ICAO: ANR, Callsign: Yanair, | UA | AVCODES |
| 174 | YEAG | YEAGERS FUEL INC | | | SCAC4 |
| 175 | YEAI | YECKS SERVICE | | | SCAC4 |
| 176 | YECT | YECTLI TRANSPORTATION INC | | | SCAC4 |
| 177 | YEDH | YEATON, DEAN H INC | | | SCAC4 |
| 178 | YEDU | TVS GROUP DMCC | | UAE | BIC |
| 179 | YEEH | YEE, HARLEY RARE COMICS | | | SCAC4 |
| 180 | YEHO | YEOHOLME TRANSPORT INC | | | SCAC4 |
| 181 | YEIN | YEADARA EXPRESS INC | | | SCAC4 |
| 182 | YEJ | Ystad - Eslöv Järnväg | 1865 - 1941 | S | svenska-lok.se |
| 183 | YEL | Summit Aviation, Inc. | Callsign: Yellowstone, | USA | AVCODES |
| 184 | YELA | YG EXPRESS LLC | | | SCAC4 |
| 185 | YELF | YELLOW FORWARDING CO | | | SCAC4 |
| 186 | YELI | YELLI, BERNARD TRUCKING | | | SCAC4 |
| 187 | YEME | YEMAN AIRWAYS | | | SCAC4 |
| 188 | YEMX | Yesera Monterrey, S.A. | added 1/1957; 10/1957; eliminated 1/1958 | | NAKINA |
| 189 | YEMX | Yesera Monterrey, S.A. | 10/57; eliminated 1/58 | | NRHS |
| 190 | YEMX | YESERA MONTERREY, SA | | | PWRC |
| 191 | YENP | YORK ENTERPRISES | | | SCAC4 |
| 192 | YEO | Foster Yeoman Limited | | GB | TRAFFIC |
| 193 | YEOU | YEOU FA CHEMICAL CO LTD | | RC | BIC |
| 194 | YEOU | YEOU FA CHEMICAL CO LTD | | | SCAC4 |
| 195 | YEREVAN | | City: Yerevan | AM | TRAFFIC |
| 196 | YESE | YES EXPRESS INC | | | SCAC4 |
| 197 | YESF | YES FREIGHT INC | | | SCAC4 |
| 198 | YESI | YES IMPORTS | | | SCAC4 |
| 199 | YESK | YESIK, EDWARD TRUCKING | | | SCAC4 |
| 200 | YESL | YES LOGISTICS CORP | | | SCAC4 |
