Class 9

Class 9, Class 09 and Class IX may refer to:
 * BR Standard Class 9F, a steam locomotive class of the United Kingdom
 * BR Standard Class 9F 92020-9
 * British Rail Class 09, a diesel locomotive class of the United Kingdom
 * Eurotunnel Class 9, an electric class locomotive
 * G&SWR 9 Class
 * GCR Class 9A
 * GCR Class 9D
 * GCR Class 9F, a steam locomotive class of the United Kingdom
 * GCR Class 9J
 * GCR Class 9K
 * GCR Class 9N, a steam locomotive class of the United Kingdom
 * GCR Class 9Q
 * GCR Class 9P
 * GNR Class J9
 * HAZMAT Class 9 Miscellaneous, a category of hazardous material
 * I-9-class submarine
 * Indian locomotive class WAG-9
 * LSWR F9 class
 * LSWR T9 class
 * MGWR Class 9
 * NSB Class 9, a standard-gauge steam locomotive class of Norway
 * NSB Class IX, a narrow-gauge steam locomotive class of Norway
 * NSB El 9, an electric locomotive class of Norway
 * O 9-class submarine
 * PGM-9-class motor gunboat
 * Prussian T 9
 * Southern Pacific class AC-9
 * Class IX (U.S. Army), Repair parts and components, including kits, assemblies and subassemblies, repairable and unrepairable, required for maintenance support of all equipment