L9

L9 may refer to:

Military

 * HMS L9, a British L class submarine
 * L9 Bar Mine, a large rectangular British anti-tank landmine
 * L9A1 51 mm light mortar, used by the British Army
 * Royal Ordnance L9, a British tank gun
 * USS L-9 (SS-49), an L-class submarine of the United States Navy

Science and technology

 * 60S ribosomal protein L9, a protein that is encoded by the human RPL9 gene
 * Level 9 Computing, a text-based game company
 * LG Optimus L9, a mobile smartphone
 * LG L9, a system on a chip for Smart TV devices
 * Motorola SLVR L9, a mobile phone

Other uses

 * Barcelona Metro line 9, in Barcelona, Spain
 * Stinson L-9, a 1940s American light utility monoplane
 * L9, IATA code of Lumiwings, a Greek airline
 * L9, then-IATA code of Teamline Air, a former Austrian airline