9 mm (disambiguation)
Introduction '''9 mm''' or  9×19mm Parabellum is a firearms cartridge. '''9 mm''' or '''9mm''' may also refer to:* "9mm" (song), David Banner song* 9 mm caliber, cartridges other than 9×19mm with 9 mm bullets* 9mm Parabellum Bullet, a Japanese rock band
Rail transport modelling * N gauge, 1:160 scale, with rails 9 mm apart, representing standard gauge* British N gauge, 1:148 scale, with rails 9 mm apart, representing standard gauge* H0e/HOn30 gauge, 1:87.1 scale, with rails 9 mm apart, representing narrow gauge* OO9, 1:76 scale, with rails 9 mm apart, representing narrow gauge in Britain* Gnine/IIp gauge, 1:22.5 scale, with rails 9 mm apart, representing minimum/miniature gauge