# K1

K1, K.I, K01, K 1 or K-1 can refer to:

## Geography

* K1, another name for Masherbrum, a mountain in the Karakoram range in Pakistan
* Kōnāhuanui 1, a mountain in Oahu, Hawaii
* K1, a small town to north of Kirkuk city, Iraq
* K1 (building), a high-rise building in Kraków, Poland

## Mathematics

* $K_{1}(R)$ denotes the first algebraic K-theory group of a ring $R$.

## Military

* Denel K1, a South African mortar
* Daewoo Precision Industries K1, a carbine of the South Korean army
* EMER K-1, a Burmese assault rifle designated EMERK
* Fokker K.I, a World War I German experimental aircraft
* Kucher Model K1, a Hungarian submachine gun
* HMS K1, a World War I British submarine
* HMS Acanthus (K01) / HNoMS Andenes (K01), a 1939 British, then Norwegian Flower-class corvette
* K1 tank, or Type 88 tank, a modern main battle tank of the South Korean military
* K-1 cart a United States Signal Corps cart for carrying signal equipment
* K 1, a designation for a Swedish cavalry regiment
* K1-class gunboat, planned World War II German gunboat
* K1, a World War II Dutch sloop operated by the German Navy
* Skoda K-1, of the Skoda K series, a World War II Czechoslovak howitzer
* USS K-1 (SS-32), a 1913 United States Navy K class of submarine
* K-1 Airfield, former name of the Gimhae Air Base
* Soviet submarine K-1
* IVL K.1 Kurki, a Finnish trainer aircraft

## Names

* An abbreviation of Keiichi Morisato, a character in the manga/anime Oh My Goddess!
* First name of Keiichi Maebara, a character in Higurashi When They Cry franchise
* K1, a nickname given to Kyler Murray (born 1997), American football quarterback

## Transportation
### Road transport

* BMW K1, a sport bike
* K-1 Attack, a Slovak sports car
* K-1 (Kansas highway), a state highway in Kansas
* London Buses route K1, a Transport for London contracted bus route
* Tatra K1, a 1967 Czechoslovakian experimental tramcar

### Steam locomotives

* Furness Railway K1, a steam locomotive class related to the Furness Railway K2
* GSR Class K1, a Great Southern Railway Irish steam locomotive
* LNER Thompson/Peppercorn Class K1, a 1949 British 2-6-0 (mogul) steam locomotive class
* LNER Class K1, a class of British steam locomotives
* NCC Class K1, a Northern Counties Committee Irish steam locomotive
* PRR K1, a Pennsylvania Railroad locomotive classification
* SR K1 class, a British 2-6-0 steam locomotive
* the first 1909 Tasmanian Government Railways K class Garratt, a type of articulated steam locomotive

### Water transport and sport

* K1 Britannia, the replica of His Majesty's Yacht Britannia built in 1893 for Commodore Albert Edward, Prince of Wales
* The class/racing number on HMY Britannia's main sail
* K1, (single kayak) a canoe racing event under the International Canoe Federation

### Other vehicles

* K-1 (rocket), an aerospace vehicle under development by Rocketplane Kistler

## Electronics

* Kawai K1, a digital synthesizer
* Magnetophon K1, the first tape recorder, produced in Germany in 1935
* Motorola KRZR K1, a mobile phone
* Sendo K1, a model of Sendo mobile phone
* Pentax K-1, a digital single-lens reflex camera
* Pentax K-01, a digital mirrorless interchangeable lens camera
* Tegra K1, an Nvidia system on a chip for mobile devices

## United States government forms

* K-1 visa, a United States immigration visa (also called the fiancé(e) visa)
* Schedule K-1, a tax form of the United States Internal Revenue Service (IRS) corresponding with Form 1065 to report one's share of income in a flow-through entity

## Music

K. 1 can designate:
* six works by Wolfgang Amadeus Mozart:
** K. 1a, an Andante in C for Keyboard
** K. 1b, an Allegro in C for Keyboard
** K. 1c, an Allegro in F for Keyboard
** K. 1d, a Minuet in F for Keyboard
** K. 1e, a Minuet in G for Keyboard
** K. 1f, a Minuet in C for Keyboard
* Kk. 1 or K. 1, a sonata for keyboard by Scarlatti; see List of solo keyboard sonatas by Domenico Scarlatti
* Kay One (born 1984), German rapper
* Kingz One, a music group created in 2003

## Miscellaneous

* Family K1, a set of New Testament manuscripts
* K1 or K-1, an abbreviation for kerosene heating fuel
* K1, a Larcum Kendall marine chronometer (1769)
* K-1, a kickboxing promotion
* Haplogroup LT or K1, a Y-chromosome DNA haplogroup
* K1, an alternative title for Kommune 1
* k1, a coefficient that encapsulates process-related factors, limiting the minimum feature size in photolithography
* K1 fund, a suspected German Ponzi-scheme
* an abbreviation for KotOR 1
* K$_1$, a common name for the vitamin phylloquinone