I8 or I-8 may refer to:
* Interstate 8, a highway in the southwestern United States
* Interstate 8 (EP), ''Interstate 8'' (EP), an extended play by Modest Mouse
* ''Resistance: Fall of Man'', a video game originally known as ''I-8''
* Straight-eight engine, an uncommon internal combustion engine
* , a submarine of the Imperial Japanese Navy
* BMW i8, a plug-in hybrid sports car
* Uppland Regiment, a Swedish Army infantry regiment disbanded in 1957
* i8, a name for the Integer (computer science)#Common integral data types, 8-bit signed integer, especially in Rust (programming language), Rust
{{Letter-Number Combination Disambiguation
