Semien Omo (English: North Omo) was a Zone in the Ethiopian Southern Nations, Nationalities, and Peoples' Region (SNNPR). It was named after the Omo River, which flows in the western area of the former zone. In 2000 it was split into three zones: Dawro, Gamo Gofa, and Wolayita; and Basketo and Konta became special woredas.
Semien Omo was bordered on the south by Debub Omo, on the west by Keficho Shekicho, on the northwest by the Oromia Region, on the north by Kembata Tembaro, on the northeast by part of the Oromia Region, on the east by the Bilate River which separated it from Sidama and another part of the Oromia Region, and on the southeast by the Amaro and Dirashe special woredas. The highest point in Semien Omo was Mount Guge (3568 m), west of Chencha. The administrative center of Semien Omo was Arba Minch; other towns included Areka, Boditi, Sawla and Sodo.
The Central Statistical Agency (CSA) reported that 8,364 tons of coffee were produced in Semien Omo in the year ending in 2005, based on inspection records from the Ethiopian Coffee and Tea authority. This represents 7.27% of the SNNPR's output and 3.7% of Ethiopia's total output.