I6
I6 or I-6 may refer to:
- Polikarpov I-6, a Soviet fighter prototype of the 1930s
- Straight-six engine, six-cylinder internal combustion engine
I 6 is a Swedish regimental designation (6th Infantry Regiment) that has been used by the following units:
- Västgöta regemente (1816–1927)
- Norra skånska infanteriregementet (1928–1963)