I9

I9, i9 or I-9 may refer to:

Science and technology

 * Intel Core i9, a line of high-performance processors
 * Gulftown, microprocessors originally rumored to be called the Intel Core i9
 * Inline-nine engine, a straight engine with nine cylinders
 * ICD-9, a coding system for medical diagnoses and procedures

Other uses

 * Form I-9, a US Citizenship and Immigration Services form
 * Air Italy (2005–2018) (former IATA code: I9), a former Italian airline
 * Interstate 9, a proposed upgrade to California State Route 99
 * Skaraborg Regiment (infantry) (designation: I 9), a Swedish Army infantry regiment disbanded in 1942
 * Japanese submarine I-9, an Imperial Japanese Navy submarine