| K | Kelvin - Potassium (Latin Kalium) - Tanker (aircraft Designation Code) | - | Astronomy |
| K | Kilo | - | Astronomy |
| K/T | Cretaceous/Tertiary Boundary | - | Astronomy |
| K9 | Canine Police Unit | - | Astronomy |
| KA | Knowledge Acquisition | - | Astronomy |
| KA | Georgian Language (ISO 639-1 Code) | - | Astronomy |
| KA | Kamov Design Bureau | - | Astronomy |
| KA | Kiloampere | - | Astronomy |
| KAF | Kandahar Air Field | - | Astronomy |
| KAL | Kalaallisut Language (ISO 639-2 Code) | - | Astronomy |
| KAN | Kannada Language (ISO 639-2 Code) | - | Astronomy |
| KARNAC | Knowledge Aided Retrieval In Activity Context | - | Astronomy |
| KAS | Kashmiri Language (ISO 639-2 Code) | - | Astronomy |
| KAT | Georgian Language (ISO 639-2 Code) | - | Astronomy |
| KATUSA | Korean Augmentation To United States Army | - | Astronomy |
| KAU | Kanuri Language (ISO 639-2 Code) | - | Astronomy |
| KAZ | Kazakh Language (ISO 639-2 Code) | - | Astronomy |
| KAZ | Kazakhstan (ISO 3166 Trigram) | - | Astronomy |
| KBE | Knight Commander Of The Order Of The British Empire | - | Astronomy |
| KBO | Kuiper Belt Object | - | Astronomy |
| KC | Kilocoulomb | - | Astronomy |
| KCK | Kansas City | - | Astronomy |
| KCL | King's College London | - | Astronomy |
| KCMO | Kansas City | - | Astronomy |
| KD | Kawasaki Disease - Kraft Dinner | - | Astronomy |
| KE | Kenya (FIPS 10-4 Country Code; ISO 3166 Digram) -Kinetic Energy - Knowledge Engineering | - | Astronomy |
| KEDO | Korean Peninsula Energy Development Organization | - | Astronomy |
| KEN | Kenya (ISO 3166 Trigram) | - | Astronomy |
| KERA | Kentucky Education Reform Act (of 1990) | - | Astronomy |
| KERMA | Kinetic Energy Released In MAterial / In MAtter / Per Unit MAss | - | Astronomy |
| KES | Kenyan Shilling (ISO 4217 Currency Code) | - | Astronomy |
| KET | Kentucky Educational Television Refers To The Network And The Production Facilities -Key English Test | - | Astronomy |
| KF | Kilofarad | - | Astronomy |
| KFC | Kentucky Fried Chicken | - | Astronomy |
| KFOR | UN Kosovo Force | - | Astronomy |
| KFUPM | King Fahd University Of Petroleum & Minerals | - | Astronomy |
| KG | Kilogram - Kongo Language (ISO 639-1 Code) | - | Astronomy |
| KG | Kyrgyzstan (FIPS 10-4 Country Code; ISO 3166 Digram) | - | Astronomy |
| KGB | Komitet Gosudarstvennoy Bezopasnosti (Russian Committee For State Security) (1954-1991) | - | Astronomy |
| KGO | Knight Of The Guelplic Order Of Hanover | - | Astronomy |
| KGS | Kyrgyz Som (ISO 4217 Currency Code) | - | Astronomy |
| KGZ | Kyrgyzstan (ISO 3166 Trigram) | - | Astronomy |
| KH | Cambodia (ISO 3166 Digram) | - | Astronomy |
| KH | Kilohenry | - | Astronomy |
| KHM | Cambodia (ISO 3166 Trigram) | - | Astronomy |
| KHM | Khmer Language (ISO 639-2 Code) | - | Astronomy |
| KHR | Cambodian Riel (ISO 4217 Currency Code) | - | Astronomy |
| KI | Gikuyu Language (ISO 639-1 Code) | - | Astronomy |
| KI | Kibi | - | Astronomy |
| KI | Kiribati (ISO 3166 Digram) | - | Astronomy |
| KIA | Killed In Action | - | Astronomy |
| KIDS | Knowledge-based Integrated Design System | - | Astronomy |
| KIK | Gikuyu Language (ISO 639-2 Code) | - | Astronomy |
| KIN | Kinyarwanda Language (ISO 639-2 Code) | - | Astronomy |
| KIR | Kiribati (ISO 3166 Trigram) | - | Astronomy |
| KIR | Kyrgyz Language (ISO 639-2 Code) | - | Astronomy |
| KISS | Keep It Simple | - | Astronomy |
| KITECH | Korean Institute Of Industrial Technology | - | Astronomy |
| KITT | Knight Industries Two Thousand | - | Astronomy |
| KJ | Kilojoule | - | Astronomy |
| KJ | Kuanyama Language (ISO 639-1 Code) | - | Astronomy |
| KK | Kabushiki Kaisha (Japanese For Stock Company | - | Astronomy |
| KK | Kazakh Language (ISO 639-1 Code) | - | Astronomy |
| KK | Kilokelvin | - | Astronomy |
| KKK | Ku Klux Klan | - | Astronomy |
| KL | Kalaallisut Language (ISO 639-1 Code) | - | Astronomy |
| KL | Kilolitre | - | Astronomy |
| KLENOT | KLE? Observatory Near Earth And Other Unusual Objects Observations Team And Telescope | - | Astronomy |
| KLM | Koninklijke Luchtvaart Maatschappij (Dutch Royal Dutch Airlines) | - | Astronomy |
| KLOC | Kilo Lines Of Code | - | Astronomy |
| KM | Comoros -Knowledge Management | - | Astronomy |
| KM | Khmer Language (ISO 639-1 Code) - Kilometre | - | Astronomy |
| KMF | Comoro Franc (ISO 4217 Currency Code) | - | Astronomy |
| KMFDM | Kein Mitleid FÂr Die Mehrheit (German No Pity For The Majority Music Band) | - | Astronomy |
| KMR | Kwajalein Missile Range | - | Astronomy |
| KN | Democratic People's Republic Of Korea (FIPS 10-4 Country Code) - Saint Kitts And Nevis (ISO 3166 Digram) | - | Astronomy |
| KN | Kannada Language (ISO 639-1 Code) | - | Astronomy |
| KN | Kilonewton | - | Astronomy |
| KNA | Saint Kitts And Nevis (ISO 3166 Trigram) | - | Astronomy |
| KNVB | Koninklijke Nederlandse Voetbal Bond (Dutch For Royal Netherlands Football Association) | - | Astronomy |
| KO | Knocked Out | - | Astronomy |
| KO | Korean Language (ISO 639-1 Code) | - | Astronomy |
| KOM | Komi Language (ISO 639-2 Code) | - | Astronomy |
| KON | Kongo Language (ISO 639-2 Code) | - | Astronomy |
| KOR | Korean Language (ISO 639-2 Code) | - | Astronomy |
| KOR | Republic Of Korea (ISO 3166 Trigram) | - | Astronomy |
| KP | Kim Possible | - | Astronomy |
| KPNO | Kitt Peak National Observatory | - | Astronomy |
| KPV | Krupnokaliberniy Pulemet Vladimorova (Russian ???? ???????????????? ??????? ??????????? | - | Astronomy |
| KPVT | Krupnokaliberniy Pulemet Vladimorova Tankoviy (Russian ???? ???????????????? ??????? ??????????? ???????? | - | Astronomy |
| KPW | North Korean Won (ISO 4217 Currency Code) | - | Astronomy |
| KQ | Kenya Airways (IATA Airline Designator) - Kingman Reef (FIPS 10-4 Territory Code) | - | Astronomy |
| KR | Kanuri Language (ISO 639-1 Code) | - | Astronomy |
| KR | Kiribati (FIPS 10-4 Country Code) - Republic Of Korea (ISO 3166 Digram) | - | Astronomy |
| KR | Krypton | - | Astronomy |
| KRW | South Korean Won (ISO 4217 Currency Code) | - | Astronomy |
| KS | Kansas (postal Symbol) - Republic Of Korea (FIPS 10-4 Country Code) | - | Astronomy |
| KS | Kashmiri Language (ISO 639-1 Code) - Kilosecond | - | Astronomy |
| KS | Kilosiemens | - | Astronomy |
| KSC | Kennedy Space Center | - | Astronomy |
