I5, I-5 or I 5 may refer to:
Computing Intel Core i5, a brand of microprocessors i5, an IBM AS/400 line of minicomputers i5/OS, previous name of the IBM i operating system
Military , a 1931 Junsen type submarine Polikarpov I-5, a Soviet fighter biplane of the 1930s I 5, a Swedish regimental designation (5th Infantry Regiment) that has been used by the following units: 2nd Life Grenadier Regiment (1816–1927) Jämtland Ranger Regiment (1928–1974, 1990–1994, 2000–2004)
Transportation Interstate 5 (I-5), a US highway Inline-five engine, or straight-five engine AirAsia India (IATA code) General Electric I-5, the "industrial" model of GE's Elec-Trak electric tractor The electric version of the BMW 5 series, BMW i5
Other uses I5 (girl group), American band in 2000-2001 Inferior Five, fictional superhero group from DC Comics
See also iPhone 5, an Apple smartphone 5I (disambiguation)