I129 or I-129 may refer to: Interstate 129, an auxiliary Interstate Highway which connects South Sioux City, Nebraska to Interstate 29 in Sioux City, Iowa Iodine-129 (I-129 or 129I), a radioactive isotope of iodine Form I-129 (Petition for a Nonimmigrant Worker) filed by employers for workers seeking a temporary nonimmigrant worker classification such as the H-1B visa, H-2A visa, H-2B visa, or L-1 visa