T9
T9 may refer to:

Military
M4 cannon, the 37 mm Automatic Gun, known as the T9 during development
M22 Locust, an airborne light tank, known as the T9 during development
German torpedo boat T9

People
Tech N9ne (born 1971), hip hop artist
Fernando Torres (born 1984), former footballer nicknamed "T9"

Physiology
Thoracic vertebra 9
Thoracic spinal nerve 9

Products
Sony Cyber-shot DSC-T9, a digital camera
Yepp, the Samsung YP-T9 MP3 player
T-9, a Ford manual transmission also known as Type 9

Transportation
Tramway T9, a tram line in Île-de-France
Former IATA code for TransMeridian Airlines
Former IATA code for Transcarga
Northern Line (Sydney), a rail service numbered T9
LSWR T9 class, a British locomotive class
Prussian T 9, a German steam locomotive
Van Hool T9, a line of touring buses

Other uses
T9 (predictive text), an input technology for mobile phones
T9, a fluorescent lamp tube format designation
A tornado intensity rating on the TORRO scale