| Abbreviation | Definition |
|---|---|
| KKRR | Knox and Kane Railroad Company |
| KKRX | Kaskaskia Regional Port District Railroad |
| KKTU | Kerr Steamship K Line |
| KKTU | Kerr Steamship 'K' Line |
| KLCU | IBJ Leasing (Containerships Ltd) |
| KLCU | IBJ Leasing Company Limited |
| KLIU | Klinge Corporation |
| KLL | Klickitat Log and Lumber (St. Regis Paper Co.) |
| KLSC | Kalamazoo Lake Shore and Chicago Railway |
| KLSC | Kalamazoo, Lake Shore and Chicago Railway |
| KLSX | Kerford Limestone |
| KLTU | K Line |
| KM | Kansas and Missouri Railway and Terminal |
| KM | Kansas and Missouri Railway and Terminal Company |
| KMCU | Mitsui O. S. K. Lines Limited |
| KMCU | Mitsui O.S.K. Lines |
| KMCX | Kerr-Mcgee Coal Corporation |
| KMEU | K Line |
| KMFX | Kaolin Mushroom Farms |
| KMRC | Kolkata Metro Rail Corporation |