U1, U.I or U-1 may refer to:

Mathematics

*U(1), the degree one '' unitary group''

Military

*U-1, the USAF and US Military's designation for the De Havilland Canada DHC-3 Otter light transport aircraft *U-1, Soviet designation for Avro 504 trainer. *Multiple German U-boats named ''U-1'' * Oberursel U.I, an early German aircraft engine *

HDMS U-1 Okręt Rzeczypospolitej Polskiej, ORP ''Dzik'' (Boar) was a British U-class submarine, U-class submarine built by Vickers Shipbuilding and Engineering Ltd, Vickers-Armstrong at Barrow-in-Furness. She was laid down on 30 December 1941 as P-52 for ...

, a Danish submarine * SM U-1, an Austro-Hungarian submarine, lead ship of the U-1 class

Entertainment

U1 Technology ''Little Fighter Online'' (LFO, Chinese: 小朋友齊打交 Online) was a fighting game for Microsoft Windows. It was popular at launch in Hong Kong, but has shown a rapid decline in popularity since. The gameplay itself was based on the earlie ...

, a game and software developing company *'' Ultima I: The First Age of Darkness'', a 1981 video game

People

* U1, alias for

Yuvan Shankar Raja Yuvan Shankar Raja or Abdul Haliq (born 31 August 1979) is an Indian film score and soundtrack composer and singer-songwriter. He mainly scores music for Tamil films. Considered a versatile composer, he is particularly known for his use of Wes ...

(born 1979), a Tamil musician and film composer *U-1, the main character in the video game ''

Gitaroo Man ''Gitaroo Man'' is a rhythm video game developed by iNiS and published by Koei for PlayStation 2. The game features visual production by Mitsuru Nakamura and an original soundtrack by Japanese band COIL. The game was released in Japan on June 2 ...

'' for the PlayStation 2/PlayStation Portable

Railways

LNER Class U1 The London and North Eastern Railway Class U1 was a solitary Beyer-Garratt locomotive designed for banking coal trains over the Worsborough Bank, a steeply graded line in South Yorkshire and part of the Woodhead Route. It was both the longest ...

, a 1924 British solitary 2-8-0+0-8-2 Beyer-Garratt locomotive *

SR U1 class The SR U1 class were three-cylinder 2-6-0 ('mogul') steam locomotives designed by Richard Maunsell for passenger duties on the Southern Railway. The fifth member of the Maunsell "family" of standardised moguls and 2-6-4 locomotives, the U1 was ...

, a class of 2-6-0 locomotives developed from the U Class

U-Bahn lines

U1 (Berlin U-Bahn) U1 is a line on the Berlin U-Bahn, which is long and has 13 stations. Its traditional line designation was BII. It runs east–west and its eastern terminus is Warschauer Straße S-Bahn station where it connects to the Schlesische Bahn. Fr ...

* U1 (Frankfurt U-Bahn) *

U1 (Hamburg U-Bahn) The U1 is a line of the Hamburg U-Bahn which has a length of . It starts in Norderstedt Mitte and leads via the city center at Jungfernstieg and Hauptbahnhof Süd to Volksdorf where it divides in two branches, leading to Ohlstedt and Gro ...

* U1 (Munich U-Bahn) * U1 (Nuremberg U-Bahn) * U1 (Vienna U-Bahn)

Technology

Secure Digital Secure Digital, officially abbreviated as SD, is a proprietary format, proprietary non-volatile memory, non-volatile Flash memory, flash memory card format developed by the SD Association, SD Association (SDA) for use in portable devices. The s ...

(SD) Cards, class of speed *

Apple U1 Apple silicon is a series of system on a chip (SoC) and system in a package (SiP) processors designed by Apple Inc., mainly using the ARM architecture. It is the basis of most new Mac computers as well as iPhone, iPad, iPod Touch, Apple TV, a ...

Other

*U1, unemployment figure released by Bureau of Labor Statistics *

U1 spliceosomal RNA U1 spliceosomal RNA is the small nuclear RNA (snRNA) component of U1 snRNP (''small nuclear ribonucleoprotein''), an RNA-protein complex that combines with other snRNPs, unmodified pre-mRNA, and various other proteins to assemble a spliceosome, a ...

, a small nuclear RNA component of the spliceosome involved in pre-mRNA splicing.